Add Absolute Volume Control support for a TV as the System Audio device

A TV will react to <Set Audio Volume Level> messages by setting the
volume of STREAM_MUSIC, unless System Audio Mode is enabled. In this
case, the TV does nothing and responds with <Feature Abort>[not in
correct mode to respond], as <Set Audio Volume Level> messages should
only be send to the System Audio device.

Test: atest HdmiCecLocalDeviceTvTest
Bug: 223131113
Change-Id: I1aac3926ffe1280344e97efcbd1dce7f9c3c3ffd