Add type used for describing the mute state

This is used by the playback notification API to inform about a
mute/unmute event and also describe the reason for mute (stream, master,
playback restricted by apops mute)

Test: dumpsys audio
Bug: 235521198
Change-Id: I22e57e78e75a276dcb60e2820ec2cf26734b93c1
3 files changed