Merge "Don't add StageChangeRecord when stage task moves to back" into main am: 557303d3d7

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2967635

Change-Id: I64532acb3e809e2a4ae014435559ec0608a4127d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>