Track the AudioManager Playback state to update the AVRCP playback state

* If the AudioManager playback configuration shows that one of the
  player's state is PLAYER_STATE_STARTED (as received in a callback
  from the AudioManager), then set the AVRCP state to
  PlaybackState.STATE_PLAYING
* Don't suppress AVRCP playback state change when no track change

Bug: b/63151260
Bug: b/66029010
Test: Manual with Bose SoundSport FW v1.3.0
Change-Id: I0878ba26a78a7e5ef52ec033386300b777a39c67
(cherry picked from commit 6822e62e)
(cherry picked from commit 98f72525)

Second Cherry-pick due to an accidental skip during a merge-conflict.