Merge "Put activity-start into its own transition when recents collecting" into udc-dev am: 70941199 am: 962b2744 am: e80abdf1 am: 4682c9e9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22873334



Change-Id: I1a13b9871263f495ed1aacbc58d2b74cf68f522c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>