Merge "Hook up split-launch to legacy transition system" into sc-v2-dev am: 5a7602f55c am: 4c02707848

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15150390

Change-Id: I46d2e5f0751797975bbb9d66c63e54677bdee5d1