Merge "Refactor PlatformCompat and related files." am: 5d37ff2d33

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1553536

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I662e0813ca02ec8a0fa569a4afde2a7db00a9e6d