Merge "Prevent NPE inside AllAppsTransitionController" into sc-dev am: d60299e19f

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/13756046

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: If70db9e65c365fe2efb0538170a7a9ffb0685fd5