Add some more public doc for MacAddress

Bug: 140807677
Test: doc-only change
Change-Id: I0f6e59eda42fd92ec34db0e9bc2d26d2e83d41d0
1 file changed
tree: 38ab900e38b32cbf7b8282fcadcee85447bb93e7
  1. core/
  2. services/
  3. tests/