Reapply "Fix EthernetManagerTest"

This reverts commit f28878b1209145c0cbc0eeb05bd12831f7e635ba.

Reason for revert: The original change was incompatible with
ag/34622357. Reapplying the fixed CL.

Bug: 432497516
Change-Id: I1b19b3336a4c938ef1adbd12c50a11903d373194
1 file changed