Change the signature of notifyInterfaceClassActivity.

This simplifies an upcoming refactoring of the notification code.
There is no change in functionality because DC_POWER_STAET_MEDIUM
was never actually used.

Bug: 112869080
Test: builds, boots
Test: atest FrameworksNetTests
Change-Id: Ie7bd145961bbd7f2a424be4299e2085da9cddc38