Merge "Send widget added and removed events to AiAi." into sc-v2-dev am: 29c3f23be5 am: 5c09d7e4cd

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/16006577

Change-Id: I68a7562ec2dd9ee355dcf5dda10e6481092024df