Merge ""Merge" activity-only transitions into ongoing recents" into udc-dev am: 6a7dca36

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22183106



Change-Id: I2cf22f646008492b2e87e98c34abd56c63676171
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>