Update Inactive Apps screen to show buckets

Show the standby bucket state and allow
toggling between the buckets.

EXEMPTED/NEVER state cannot be changed and item
will be grayed out.

Bug: 72728900
Test: Settings>Dev>Standby apps

Change-Id: Id38e6c6483b9b6aaafca5e2a0b6b82756fb28b1f