Also update the test to ensure mFactory.hasInterface is mocked to match
mFactory.getInterfaceState: previously it would be called by the factory
in the mocked getInterfaceState, but the new code calls it directly.
Bug: 171872016
Test: atest EthernetManagerTest
Change-Id: I9ac959f181c88a7992991923b98a836f2833fa88
(cherry picked from commit f33f276b29)
Merged-In: I9ac959f181c88a7992991923b98a836f2833fa88