Merge "Add the DefaultItemAnimator, without change animations" into sc-dev am: d9abe11b92 am: dfe6f44c05 am: ada3a97c0a

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/14736372

Change-Id: I51aa61dfacc629aa5a701c9820ab5f71e32c3c25