audio policy: fix multiple device volume

Whem multiple devices are selected by a strategy,
apply volume to all these devices when one of them is changed by
setStreamVolumeIndex() API.

Also only consider devices supported by current output profile
in checkDeviceMuteStrategies() to avoid muting a stream because of
devices connected to another output stream.

Bug: 17507571.

Change-Id: I83ef9fb7f294214d30f7f890db44c64ece3be387