Add channel to playback notification am: de0d6c3bfd am: e4acf5e340 am: e25a3b720d am: 5de20a2df0

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Car/LocalMediaPlayer/+/1797328

Change-Id: I649781fb068a57c7c90fd128c4313351c3348041