Use public API instead of hidden API in EthernetTracker am: a8b818a487

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/net/ethernet/+/1649303

Change-Id: I55ce6d9e45e35629e1b50eed9fb1ea4acb64f564
tree: 9eaa83535c8c072e6e01b15f5581a1f46a98efd3
  1. service-t/
  2. tests/