Merge "Clarify ResolverActivity inheritance contract." into tm-qpr-dev am: a1355cd0ff

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/IntentResolver/+/21377183

Change-Id: Iba123f982922fd043b61ad6199d043c3ffb0ff33
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>