Making EthernetNetworkSpecifier public

Bug: 210485380
Test: atest EthernetServiceTests
atest CtsNetTestCasesLatestSdk

Change-Id: Ic0b7a3360745632eb024a97692e49f6c8dafa3ee
Merged-In: Ic0b7a3360745632eb024a97692e49f6c8dafa3ee
3 files changed