Merge "Clear WidgetCell#mItem before recylcing a WidgetCell" into sc-v2-dev am: ac21df2246

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15242987

Change-Id: I06cc046c510ed25c57505b9c64baf525c72ca4b9