Allow usage of SdkLevel in the framework/wifi services

This is necessary for EthernetNetworkFactory because it uses
the static lib NetworkFactory which needs to test where it runs.
Wifi services also need this for its own factories.

Bug: 183902758
Test: ClientModeImplTest
      OemWifiNetworkFactoryTest
      TelephonyNetworkFactoryTest
      UntrustedWifiNetworkFactoryTest
      WifiNetworkFactoryTest
Change-Id: I73cc38d7857934fe50995c666915662de4c154ce