hal: support car audio stream for bus devices

Add support for car audio streams and usecases
including media, system notification, navigation
guidance and phone.
The car audio streams are routed to bus devices
with assigned address, which is defined in audio
policy configuration. This enables dynamic mixing
and routing done by Android car framework from
application to AudioFlinger and audio HAL.

Change-Id: I583fc7b5f2e8850b064a3cde5f93693b16c47841