Merge "Use ArraySet#add() instead of ArraySet#append()" am: 627c6a5258

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1615181

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I1991567f130f3afee6c6bcb78a9254b45e14f6e4