AVRCP Controller Audio Focus gain behavior

When focus is lost (due to Transient loss) and music was playing we need
to pause the remote device such that we can resume audio at the same
place when focus is gained.  Only do this when we know the state should
be playing rather than just an incoming audio stream.

Bug: 67913930
Test: Play music, generate transient loss
Change-Id: I834fce6ad10d73f7836f4cb916633fd945c6c8b0