[automerger skipped] Make Ethernet interfaces more testable. am: fb336e9296 -s ours am: 523093a1ff -s ours

am skip reason: Change-Id I86eef7a93267f800dbfc8eafd307effa76a344ca with SHA-1 841195a103 is in history

Change-Id: Iec8edbba782a10b8d5c2b8c740d265dc2c11e2a1
tree: a02713025e69b8de6354fed91802b443f648442c
  1. service-t/
  2. tests/