Merge "Try to fix IndexOutBoundsException in Task#removeChild" into rvc-dev am: e938c572b7 am: f6bc5e256e am: 05e00902aa am: eb9e44f72d

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

Change-Id: Ica40f22fbc400d916ce91cad0ab5f90ee90825b0