Merge "Try to fix IndexOutBoundsException in Task#removeChild" into rvc-dev am: e938c572b7 am: f6bc5e256e am: 71ef79b25a

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

Change-Id: I2c7a757201eba0d6a3806e3395ea5d910b958ccb