service.pid properties of ManagedServiceFactory services must be used as factory PIDs

If a ManagedServiceFactory service is registered which implements the MetaTypeProvider interface the service.pid property value(s) of the service are used to augement the providing bundle's MetaTypeInformation.

In the case of ManagedServiceFactory services the service.pid property must be used as factory PIDs where currently they are used as singleton service PIDs.

This may create confusion and in fact also breaks OSGi CT tests.