audio policy: improve support for direct outputs

Add the capability to query supported parameters for
direct outputs after a device is connected. This allows
to dynamically update the output profile for devices like
HDMI where the capabilities depend on the connected sink.

Also added very verbose log mode for volume and mute.

Change-Id: I1d4ba8e7dbc3e1af883582857ce93240441e551c
3 files changed