Merge "Avoid locking mChanges when not necessary" into sc-dev am: 7dfe7b74 am: 329d66aa am: 8e92cdb5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/14971030

Change-Id: Ief03fd08c3efc6ca4f0c6f21efe00f4d62d50e02