Merge "Add OnLayoutCompleted() Listener." into tm-qpr-dev am: fd7afb707a

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/20432434

Change-Id: I21481a4769668479d161f5557caddaa8b7b85edf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>