Merge "Add some more public doc for MacAddress" into rvc-dev am: 2ddb47fa19

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12107302

Change-Id: I2dedf3b86e1ecdb36ebfe67397de9664057fc786
tree: 2ea86038a40a54279747fe61c450dd5302783a27
  1. core/
  2. services/
  3. tests/