Merge "merge onReject into onDisconnect; propagate cause" into udc-dev am: 23e1b1de

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/21482671



Change-Id: I57eb13a528dc46f237368d09cabc8e0251b9c23f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>