Add Ethernet, TestNetworkSpecifier API am: 7f11b46a43 am: f680bb763a

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1574300

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I63159846579c43c721eeb86c9a55faa3f2888be8