Allow usage of SdkLevel in telephony

This is necessary for TelephonyNetworkFactory because it uses
the static lib NetworkFactory which needs to test where it runs.

Bug: 183902758
Test: ClientModeImplTest
      OemWifiNetworkFactoryTest
      TelephonyNetworkFactoryTest
      UntrustedWifiNetworkFactoryTest
      WifiNetworkFactoryTest
Change-Id: I765bcb17901a2c9862d5879d524cbf522b6c7526