Merge "Fix NPE inside REcyclerViewFastScroller" into sc-dev am: 8c0f8fba9c am: 4b92c20bc6

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14966513

Change-Id: I06218e1ad60890c4f3168805760395ee73e60b9b