AVRCP Controller transient loss while idle

While gaining and losing focus due to transient focus requests ensure
Bluetooth restores to the correct playback state.  This corrects issues
that could arise during non media sonification durring a transient
focus loss.

Bug: 136092891
Test: atest com.android.bluetooth.a2dpsink.A2dpSinkStreamHandlerTest
Change-Id: I58997b3b8b96da309ff4c31a2b3039dccf9b3578