Add a new verison of onDiscoveryPreferenceChanged

This new version sends per-app details to route providers (that have
permission to see them), in addition to the composite
RouteDiscoveryPreference that the current version already sends.

Bug: 402802435
Flag: com.android.media.flags.enable_route_visibility_control_api
Test: atest MediaRouter2HostSideTest
Change-Id: Ic455e5d9ea58601704675381e32f44cc71cc6007