Merge "(Re-Introduce locking)[TEMP] Re-Introduce synchronization locking" am: 14087b39d1 am: b646fcd689 am: 9723c61343

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2036103

Change-Id: Ic5d77ad3026b4fc4a960e33f15d2f4872a776f61