Use the AudioManager Playback state when playstate is null

For some music plyers, getPlaybackState will return null.
If a2dp is suspended by remote now, and playState is null,
updatePlayStatusToStack will not be called, and a2dp cannot
be started.

Change-Id: Ieade515d741cd9f3782fbd4c05bcf3fcbde2173d
CRs-Fixed: 2253246
1 file changed