The service is merely announced but trying to request a session always causes a
Service_denied exception. This helps in scenarios where the client is
won't open a session anyway but expects the service to be available. This is
considered a temporary solution.
Ref #4419
The 'black_hole' component provides dummy implementations of common
session interfaces.
At this time, only the 'Audio_out' session is provided if enabled
in the configuration of the component:
<config>
<audio_out/>
</config>
Issue #3653
