Rename logIfEthernetNotStarted to throwIfEthernetNotStarted am: 038c80551e am: 6a90204a43 am: 02ef6c6aa4

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/net/ethernet/+/2018415

Change-Id: Id127882a7da91cdd0b7abec5c68bef693c9f80f2
tree: d056f65b9dcbc0294a3ddc28d83551f865f16e4b
  1. service-t/
  2. tests/