update android config: migrate gradle to kts, upgrade firebase plugins, fix edge-to-edge

- migrate settings.gradle, build.gradle, app/build.gradle to kotlin dsl (.kts)
- upgrade java/kotlin compatibility from 1.8 to 17
- upgrade firebase gradle plugins (google-services 4.4.4, crashlytics 3.0.6, perf 2.0.2)
- remove jetifier, add gradle caching and parallel builds
- fix windowDrawsSystemBarBackgrounds for edge-to-edge at targetSdk 36
- add dataExtractionRules for android 12+ backup compliance
- use layout.buildDirectory api (replaces deprecated buildDir)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

android/app/build.gradle

@@ -1,60 +0,0 @@
-plugins {
-    id "com.android.application"
-    // START: FlutterFire Configuration
-    id 'com.google.gms.google-services'
-    id 'com.google.firebase.firebase-perf'
-    id 'com.google.firebase.crashlytics'
-    // END: FlutterFire Configuration
-    id "kotlin-android"
-    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
-    id "dev.flutter.flutter-gradle-plugin"
-}
-
-def keystoreProperties = new Properties()
-def keystorePropertiesFile = rootProject.file("key.properties")
-if (keystorePropertiesFile.exists()) {
-    keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
-}
-
-android {
-    namespace = "com.tommychow.frosty"
-    compileSdk = flutter.compileSdkVersion
-    ndkVersion = flutter.ndkVersion
-
-    compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_1_8
-        targetCompatibility = JavaVersion.VERSION_1_8
-    }
-
-    kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8
-    }
-
-    defaultConfig {
-        applicationId = "com.tommychow.frosty"
-        // You can update the following values to match your application needs.
-        // For more information, see: https://flutter.dev/to/review-gradle-config.
-        minSdk = flutter.minSdkVersion
-        targetSdk = flutter.targetSdkVersion
-        versionCode = flutter.versionCode
-        versionName = flutter.versionName
-    }
-
-    signingConfigs {
-        release {
-            keyAlias keystoreProperties["keyAlias"]
-            keyPassword keystoreProperties["keyPassword"]
-            storeFile keystoreProperties["storeFile"] ? file(keystoreProperties["storeFile"]) : null
-            storePassword keystoreProperties["storePassword"]
-        }
-    }
-    buildTypes {
-        release {
-            signingConfig signingConfigs.release
-        }
-    }
-}
-
-flutter {
-    source = "../.."
-}

android/app/build.gradle.kts

@@ -0,0 +1,60 @@
+import java.io.FileInputStream
+import java.util.Properties
+
+plugins {
+    id("com.android.application")
+    id("com.google.gms.google-services")
+    id("com.google.firebase.firebase-perf")
+    id("com.google.firebase.crashlytics")
+    id("kotlin-android")
+    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
+    id("dev.flutter.flutter-gradle-plugin")
+}
+
+val keystoreProperties = Properties()
+val keystorePropertiesFile = rootProject.file("key.properties")
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(FileInputStream(keystorePropertiesFile))
+}
+
+android {
+    namespace = "com.tommychow.frosty"
+    compileSdk = flutter.compileSdkVersion
+    ndkVersion = flutter.ndkVersion
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = JavaVersion.VERSION_17.toString()
+    }
+
+    defaultConfig {
+        applicationId = "com.tommychow.frosty"
+        minSdk = flutter.minSdkVersion
+        targetSdk = flutter.targetSdkVersion
+        versionCode = flutter.versionCode
+        versionName = flutter.versionName
+    }
+
+    signingConfigs {
+        create("release") {
+            keyAlias = keystoreProperties["keyAlias"] as String?
+            keyPassword = keystoreProperties["keyPassword"] as String?
+            storeFile = keystoreProperties["storeFile"]?.let { file(it) }
+            storePassword = keystoreProperties["storePassword"] as String?
+        }
+    }
+
+    buildTypes {
+        release {
+            signingConfig = signingConfigs.getByName("release")
+        }
+    }
+}
+
+flutter {
+    source = "../.."
+}

android/app/src/main/AndroidManifest.xml

@@ -13,7 +13,8 @@
         android:label="Frosty"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher"
-        android:allowBackup="false">
+        android:allowBackup="false"
+        android:dataExtractionRules="@xml/data_extraction_rules">
         <activity
             android:name=".MainActivity"
             android:exported="true"

android/app/src/main/res/values-night-v31/styles.xml

@@ -4,7 +4,7 @@
     <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
         <item name="android:forceDarkAllowed">false</item>
         <item name="android:windowFullscreen">false</item>
-        <item name="android:windowDrawsSystemBarBackgrounds">false</item>
+        <item name="android:windowDrawsSystemBarBackgrounds">true</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
     </style>
     <!-- Theme applied to the Android Window as soon as the process has started.

android/app/src/main/res/values-night/styles.xml

@@ -7,7 +7,7 @@
         <item name="android:windowBackground">@drawable/launch_background</item>
         <item name="android:forceDarkAllowed">false</item>
         <item name="android:windowFullscreen">false</item>
-        <item name="android:windowDrawsSystemBarBackgrounds">false</item>
+        <item name="android:windowDrawsSystemBarBackgrounds">true</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
     </style>
     <!-- Theme applied to the Android Window as soon as the process has started.

android/app/src/main/res/values-v31/styles.xml

@@ -4,7 +4,7 @@
     <style name="LaunchTheme" parent="@android:style/Theme.Light.NoTitleBar">
         <item name="android:forceDarkAllowed">false</item>
         <item name="android:windowFullscreen">false</item>
-        <item name="android:windowDrawsSystemBarBackgrounds">false</item>
+        <item name="android:windowDrawsSystemBarBackgrounds">true</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
     </style>
     <!-- Theme applied to the Android Window as soon as the process has started.

android/app/src/main/res/values/styles.xml

@@ -7,7 +7,7 @@
         <item name="android:windowBackground">@drawable/launch_background</item>
         <item name="android:forceDarkAllowed">false</item>
         <item name="android:windowFullscreen">false</item>
-        <item name="android:windowDrawsSystemBarBackgrounds">false</item>
+        <item name="android:windowDrawsSystemBarBackgrounds">true</item>
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item>
     </style>
     <!-- Theme applied to the Android Window as soon as the process has started.

android/app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-extraction-rules>
+    <cloud-backup>
+        <exclude domain="root" path="."/>
+    </cloud-backup>
+    <device-transfer>
+        <exclude domain="root" path="."/>
+    </device-transfer>
+</data-extraction-rules>

android/build.gradle

@@ -1,18 +0,0 @@
-allprojects {
-    repositories {
-        google()
-        mavenCentral()
-    }
-}
-
-rootProject.buildDir = "../build"
-subprojects {
-    project.buildDir = "${rootProject.buildDir}/${project.name}"
-}
-subprojects {
-    project.evaluationDependsOn(":app")
-}
-
-tasks.register("clean", Delete) {
-    delete rootProject.buildDir
-}

android/build.gradle.kts

@@ -0,0 +1,24 @@
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+val newBuildDir: Directory =
+    rootProject.layout.buildDirectory
+        .dir("../../build")
+        .get()
+rootProject.layout.buildDirectory.value(newBuildDir)
+
+subprojects {
+    val newSubprojectBuildDir: Directory = newBuildDir.dir(project.name)
+    project.layout.buildDirectory.value(newSubprojectBuildDir)
+}
+subprojects {
+    project.evaluationDependsOn(":app")
+}
+
+tasks.register<Delete>("clean") {
+    delete(rootProject.layout.buildDirectory)
+}

android/gradle.properties

@@ -1,3 +1,4 @@
 org.gradle.jvmargs=-Xmx8G -XX:MaxMetaspaceSize=4G -XX:ReservedCodeCacheSize=512m -XX:+HeapDumpOnOutOfMemoryError
 android.useAndroidX=true
-android.enableJetifier=true
+org.gradle.caching=true
+org.gradle.parallel=true

android/settings.gradle

@@ -1,28 +0,0 @@
-pluginManagement {
-    def flutterSdkPath = {
-        def properties = new Properties()
-        file("local.properties").withInputStream { properties.load(it) }
-        def flutterSdkPath = properties.getProperty("flutter.sdk")
-        assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
-        return flutterSdkPath
-    }()
-
-    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
-
-    repositories {
-        google()
-        mavenCentral()
-        gradlePluginPortal()
-    }
-}
-
-plugins {
-    id "dev.flutter.flutter-plugin-loader" version "1.0.0"
-    id "com.android.application" version "8.9.1" apply false
-    id "org.jetbrains.kotlin.android" version "2.1.0" apply false
-    id "com.google.gms.google-services" version "4.3.15" apply false
-    id "com.google.firebase.firebase-perf" version "1.4.2" apply false
-    id "com.google.firebase.crashlytics" version "2.9.9" apply false
-}
-
-include ":app"

android/settings.gradle.kts

@@ -0,0 +1,28 @@
+pluginManagement {
+    val flutterSdkPath = run {
+        val properties = java.util.Properties()
+        file("local.properties").inputStream().use { properties.load(it) }
+        val flutterSdkPath = properties.getProperty("flutter.sdk")
+        require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+        flutterSdkPath
+    }
+
+    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
+
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("dev.flutter.flutter-plugin-loader") version "1.0.0"
+    id("com.android.application") version "8.9.1" apply false
+    id("org.jetbrains.kotlin.android") version "2.1.0" apply false
+    id("com.google.gms.google-services") version "4.4.4" apply false
+    id("com.google.firebase.firebase-perf") version "2.0.2" apply false
+    id("com.google.firebase.crashlytics") version "3.0.6" apply false
+}
+
+include(":app")