Merge "Add in-task activity transition metrics" into udc-dev am: 648caea2

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23211056



Change-Id: I1a0f25f1ce59ba81a9d97400c410592ae92d89f7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>