Merge "Try to fix IndexOutBoundsException in Task#removeChild" into rvc-dev am: e938c572 am: 57f60c23 am: ef2e08ce am: fb183101

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11836345

Change-Id: Ibbede185dd55aae3c49cd20118e68ca20d624407