Adjust Photo Picker button placement and text

Put the "All photos" button below the other buttons. After the user
selects photos, change text to be "more photos". For apps that don't
support photo picker, grant USER_SELECTED first, then apply state to
READ_MEDIA_IMAGES/VIDEO. When clicking "don't allow more", no longer
revokes USER_SELECTED. If the user tries to revoke in settings while in
the false grant state, this now works properly.

Bug: 270705891
Bug: 268050719
Bug: 270700724
Fixes: 270700735
Test: atest PhotoPickerPermissionTest
Change-Id: If48cc096a0fcf51c0e884151cf8c59747403c69f
Merged-In: If48cc096a0fcf51c0e884151cf8c59747403c69f