Add the default XML audio policy configuration file for all targets
and control its usage by the flag USE_XML_AUDIO_POLICY_CONF.
CRs-Fixed: 1015136
Change-Id: If1c5d9abc6d6c882092c91c15546e25e9f7ae634
Move audio specific device overlay to audio HAL.
This helps remove dependency from other overlays and also
does not affect other subsytems.
Change-Id: I5f55f48905bd09575265f48e8b3a5a24eee278ed