Update Audio Policy Manager for remote submix

Define a new forced mode to route media to remote submix.
Update media routing rules according to mode.
Modify device connection management for remote submix.

Note that this CL doesn't implement changes to not prevent audio
 recording when WFD is on, as audio recording is currently limited
 to one input.

Change-Id: I458fe1802705da2d091ff82e536dc3e7f092f291
3 files changed