Remove the stub ethernet service from Connectivity module.

The stub ethernet service lib will be useless after removing all legacy
dependencies on ethernet-service.jar, so delete it from Connectivity
module as well.

Bug: 210586283
Test: m
Ignore-AOSP-First: avoid merge conflicts
Change-Id: Ica60df1140bf3f7345e61d642c9e9b706602c50b
3 files changed