Merge "Only update default home when the preferred home activity is modified."...

Merge "Only update default home when the preferred home activity is modified." into sc-dev am: bfdcaaf2 am: 17d78b32 am: 46b47097

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14314665

Change-Id: I77f894f4a952ae9be90a66c57206b497212b7028