Merge "Use ArraySet#add() instead of ArraySet#append()" am: 55793cc0cb am: 8d07cea94a

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I4418327b7201e31620a71b693a70403889a25fbf