The RepositoryManagement uses the new Whiteboard#track(Class,Map) method to get services with given role. When the OSGi implementation of the whiteboard is being used, the filter is transformed into OSGi filter expression. Particularly, the role property is being used to get the RevisionGCMBean of the right type.
However, the RevisionGCMBean role is being set as a part of the jmx.objectname property, not a separate property. The jmx.objectname property has following form:
Because of that, an attempt to call the RepositoryManagement#startRevisionGC() method (or its parametrized version) fails.