Merge changes from topics "CecConfigPowerStateChangeOnActiveSourceLost", "CecConfigSendStandbyOnSleep", "CecConfigSystemAudioModeMuting"

* changes:
  [CEC Configuration] Port 'system_audio_mode_muting'
  [CEC Configuration] Port 'power_state_change_on_active_source_lost'
  [CEC Configuration] Use CEC Config API in the 'send_standby_on_sleep' option