Fix media state update issues

- Allow media data updates if `active` status changes
- Update `lastActive` when PlaybackState is updated directly via the session

Without these changes, some updates would be skipped by
MediaProcessingHelper#isSameMediaData, resulting in unexpected state and/or
ordering in the carousel.

Bug: 404532173
Fixes: 421445708
Test: manual - repro steps in bug
Test: atest LegacyMediaDataManagerImplTest MediaDataProcessorTest
Flag: EXEMPT bugfix
Change-Id: Ia5aa3dfa0f6cbdb0bab87c7a22c9ab949ceeefdb