audio policy: apply default device volume

Make sure that we apply default device volume to
active outputs in case no specific volume for selected
device is received afterward.

Bug: 9760269.
Change-Id: I216de40396e1075e77493c97e8b192cd3a31d546
Merge tag 'android-4.3_r2.2' into jellybean-mr2.1

Android 4.3 release 2.2

Conflicts:
	audio/AudioPolicyManagerBase.cpp

Change-Id: I6f9238d8128a6e7be0fa138f4548adcd75d0c2a9