Disable RevisionGCMBean registration for non primary SegmentNodeStore

As discussed here untill OAK-5309 is not resolved we need to disable registration of RevisionGCMBean for non primary SegmentNodeStore such that RevisionGC for primary NodeStore can work properly.

So for 1.6 release

1. SegmentNodeStoreServiceFactory would not register RevisionGCMBean in OSGi
2. A user can still perform the revision gc by looking up SegmentRevisionGC service
3. Primary nodestore RevisionGCMBean would be registered as being done currently