Merge "Add null check before detach content view from dragView at onDropComplete" into sc-dev am: 5b786ca88d am: f5555fcb8e am: b134e677b9

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

Change-Id: I2c84f14f5ca906add555e711724cb8bf297037fa