Adopts new API according to API review feedback. The outcome receiver can later be removed from most of the ethernet code; in a perfect world, a result can be generated and an exception captured directly from EthernetServiceImpl. This will greatly simplify the current implementation. Bug: 220017952 Test: atest EthernetServiceTests Change-Id: Id8fadfed9fcfd22f04f6d7c3460b5956e571e01f