Merge "Report user_cancellation when the user back scroll from the UI...

Merge "Report user_cancellation when the user back scroll from the UI activity" into udc-dev am: b21390f0 am: 366340e6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22980754



Change-Id: I9aa592358b00db587634db7700219794ad2fb873
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>