Merge "Handle ringback changes between call state changes." into sc-dev am: 632f4e1a am: 5fd55f78 am: 7e01decb

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/15029523

Change-Id: I7143ead78c4653bd6f9d6ee9f9b2e21696307eb4