Merge "Add some more public doc for MacAddress" am: a9c0a7e2e2 am: 3b3c6ffdc2 am: 074d5a8e8a

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1354447

Change-Id: I52460b43a5d225668714c44fb5804899feb3b83a
tree: 1a2f9dedee15ebb165d955bb4f36bb3f46aa4290
  1. core/
  2. services/
  3. tests/