Merge "Do not register event until entering the state" into udc-dev am: 69f0e4c2 am: 580d29f2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/21617344



Change-Id: I7c6da41d283f1763ed409aade3d7185b2f1f5e2e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>