Merge "Revert "Clean up IMS based interfaces to use a push model instea..."" am: 8827badd30 am: 9a8e4bf6f1 am: a6bc5361b7 am: 9123ff8c6e

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1443078

Change-Id: Ia9d94fda9dc85ad0f07cd251dbdd1632b8946a4d