Add support for loading a static overrides file located in /product. am: ed60ceba22 am: b470b0d67e

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1614848

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ib4d81116d58c4821b157d9c97fd5ec59af26fc03