Ensure background perm granted last, revoked first

Ensure that background permissions are always granted after foreground
permissions, and are revoked before. Fixed job queueing, and made more informative PermState
toString. Added small delay to AppPermissionFragment updating, to deal
with "Ask every time" flashing.
Fixes: 149267332
Fixes: 148944164
Test: Manual

Change-Id: I8b9743ab5d29522d14331886b8f2bacdf9edf78c