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

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

Change-Id: Iec09ea3cf74899e6484f2fe2e5c8114ef579a33e