Refactor codes for AlbumsTabFragment

- Extract the TabFragment
- Rename BaseItemHolder to BaseViewHolder
- Modify the onItemClick for single select in PhotosTabFragment
  Add clearSelectedItems in PickerViewModel
- Add PhotosTabItemDecoration to adjust the gap of RecyclerView
- Support dark theme on date header
- Change the position of the check icon and the badges in RTL

Test: atest PickerViewModelTest
Test: screenshot on b/191746644
Bug: 191746644
Bug: 191127346
Bug: 191937323
Change-Id: Ie099a56104d7ee2f00acfac4566e898f4e2d8b29
Merged-In: Ie099a56104d7ee2f00acfac4566e898f4e2d8b29
(cherry picked from commit 34652dc00e7e2e917190a206530384f1a6d9e07f)
21 files changed