Support hidden audio usage in fade manager configuration

USAGE_VIRTUAL_SOURCE is a valid audio usage but is neither
sdk nor system type. Add a hidden api to check such cases
and support them in fade manager configurations.

Bug: 329304462
Bug: 307354764
Test: atest -c FadeManagerConfigurationUnitTest
Change-Id: I9e65cbec654cebdd5a92800a0bf5c645db480acc