[automerger skipped] Move IMS to a listener type model instead of a poll model am: e3ae65a5e4 am: 982808caf3 am: f56303e559 am: 9dab26b03e -s ours

am skip reason: Change-Id I81629d32ab995a70d8d5795351890e6d89495664 with SHA-1 67b3e041fd is in history

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telephony/+/1449136

Change-Id: I788e9daddfafb8033329ed5bac2210456f32b19f