feat/fake-barge-in

[JarbasAl]

lowers global volume during recording, to ensure OVOS can hear the user

• when a volume message is detected -> track default volume (set by user)
• when recording starts -> lower volume
• when recording ends -> restore to previous default volume

{
  "listener": {
    "fake_barge_in": true,
    "barge_in_volume": 30
  }
}

NOTE: "barge_in_volume" from 0-100

[goldyfruit]

Working for me, volume goes from 80% to 30% when record begins and got back to 80% when record ends.