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

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

Change-Id: I573f530b0ce673f7cff3a39d7c54660fbee5fcf1