Merge "Try to fix IndexOutBoundsException in Task#removeChild" into rvc-dev am: e938c572 am: f6bc5e25 am: 05e00902

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

Change-Id: Id018e52b9288fa2ea381a2aa6110ea0f3db78890