add additional audio properties

- AUDIO_FOCUS_EXT_SYNC for external sync of focus
- AUDIO_STREAM_STATE for notifying stream state
- AUDIO_PARAMETERS for car audio parameters
- AUDIO_VOLUME_EXT_SYNC for external sync of volume

bug: 32371653, 32371120
Test: build only for now, will add tests in car service layer later
Change-Id: I40ae16c40827a0240bf74714d3be333fd20424c5
1 file changed