Use public API instead of hidden API in EthernetTracker am: a8b818a487 am: 752d035896

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

Change-Id: I434cd8b952dabd5aa86b7a4e84af02d23f3543b0
tree: 9eaa83535c8c072e6e01b15f5581a1f46a98efd3
  1. service-t/
  2. tests/