Merge "Revert "Revert "Only update default home when the preferred home...

Merge "Revert "Revert "Only update default home when the preferred home activity is modified.""" into sc-dev am: a2547e30

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14478022

Change-Id: I90f40eb4c45f06ae77eac488a34990bc2986e550