Merge "Handle demo mode and apm error scenarios" into udc-dev am: 27e26abd am: 15e39cec

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/opt/telephony/+/22862326



Change-Id: Ifc21d479a652b610cb2bbc1d09ae9ddf87ecdce2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>