The new OplogVisibilityManager has global/service scope (it is a decoration on the ServiceContext) and must be initialized in the correct location in the startup logic for mongod.

1. The OplogVisibilityManager should be owned or initialized by the ReplicationCoordinatorExternalStateImpl which is, in turn, created by setup logic inside mongod_main
2. The initialization logic must acquire the RecordStore pointer to the oplog collection, using the same approach other call sites use - and provide this pointer to the OplogVisibilityManager along with the current oplog timestamp during construction.