Merge "Keep the task in main stage at top after dismissed split due to fold" into sc-v2-dev am: 7b8f6bf5b2 am: 3d46c32365

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14928714

Change-Id: I87a9a42b873c08f53c89c4e5df8b7795ff2078af