Merge "Fix the root task of secondary split screen could be overwritten." into rvc-dev am: 67a056a94c am: 5406617bb7

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11716093

Change-Id: Ia623d040dd809a477f525f3b7db557a1dd1a65bd