[snapshot] optimizing WatchedArrayList snapshot am: d5c4c550 am: fb598827...

[snapshot] optimizing WatchedArrayList snapshot am: d5c4c550 am: fb598827 am: 027bde80 am: 754bb014

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18185712



Change-Id: I1d6a7693325629701483a13df8e63721406feb64
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>