Change network management listener to outcome receiver

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
6 files changed
tree: f750c12a9873d2a8a64db37b081480549004adbe
  1. service-t/
  2. tests/