Merge "Hook up split-launch to legacy transition system" into sc-v2-dev am:...

Merge "Hook up split-launch to legacy transition system" into sc-v2-dev am: 5b003d97 am: 884bd51e

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15138014

Change-Id: Iac1f788b593b94b552049575d8e5811c8e75a40c