Merge "Return the correct root task when start activity from recents" into...

Merge "Return the correct root task when start activity from recents" into sc-v2-dev am: 83c1ab8a am: 28c84452

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15799665

Change-Id: I9c2ed10d948c336ff6a669d526c5da70c5c179d5