Being an extension on the DiskUtil couples to a class at a different abstraction
layer without really needing to. Created PermissionRequestHelper as a place to
put similar requests if needed in the future.
(cherry picked from commit 3b7ed9bc6d99c9822f3051f3696fb8359b4a8f8a)
# Conflicts:
# app/src/main/java/eu/kanade/tachiyomi/ui/browse/BrowseTab.kt
