Write tests for AllAppPermissionsFragment

- Adding/removing permissions while fragment is visible
- Close on app uninstall

Bonus:
- Factored out common methods into EspressoPreferenceUtils
- Fixed two issues in AllAppPermissionsFragment
  - Fragment can now handle apps without platform runtime permissions
  - Fragment now closes when app is uninstalled

Bug: 153792195
Test: atest AllAppPermissionsFragmentTest
Change-Id: I70616c4e79fa1f0b440619c28da976ca613005f7