Merge "Skip null surface when validating transition" into udc-dev am: 4bc363b9 am: a56a9d9a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23765883



Change-Id: I4192a3955c86dd09f4eb09f53bd79782379a993e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>