Merge changes I57ced3b6,Id988ed81,I219bd8f8,I449a775b,I86461203, ...

* changes:
  Add DetectTvSystemAudioModeSupportAction
  Add tests for HdmiAudioSystemClient
  Fix test failure at HdmiCecLocalDeviceAudioSystemTest.
  Fix test failure for SystemAudioInitiationActionFromAvrTest.
  Checking SYSTEM_AUDIO_CONTROL_ON_POWER_ON property when power on.
  Handle atom power off.
  Add SystemAudioInitiationActionFromAvr
  Handle atom wake up: bring System Audio Control on.
  Send audio status at most once per 500 ms
  Send <Report audio status> CEC commands when it's changed