Mark EthernetManagerTest as @ConnectivityModuleTest

The test will fail on T without an updated connectivity module, as it
uses new behavior implemented by a newer module version, such as
TestNetworkManager#createTapInterface(boolean, boolean).

Bug: 236558929
Change-Id: Ia74a31c8f7aabb4aae8eead5bba9f31cb7f2dd8d
Test: atest EthernetManagerTest
1 file changed