Merge "Add null check before detach content view from dragView at onDropComplete" into sc-dev am: 5b786ca88d am: f5555fcb8e

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15042822

Change-Id: I6101875d35cafb8664a0f8f07d5a127a2e37189c