A2dp: Synchronize audio, native and adapter service

During BT off mAudioManager, mA2dpNativeInterface
and mAdpaterService become null asynchronously
which is leading to fatal.
Now mActiveDevice lock will protect mAudioManager,
mA2dpNativeInterface and mAdapterService.

CRs-Fixed: 2488194
Change-Id: Ia32a900a1dc5dd1cb91edec805f50164322f7a87
1 file changed