A Subscriber is used to identify a service that is capable of deleting subscriptions. The
Subscriber must have created the subscription being deleted and maintained a reference to its
ServiceRegistration in order to be able to delete the subscription.
Deletes a subscription with the specified ID. Subscription deletion includes unregistering the
Subscription's OSGi service, its associated DurableSubscription OSGi service (if any), and
removing the subscription from the internal hashmaps maintained by the Subscriber.
subscriptionId - the globally unique UUID for a subscription
true if subscription successfully deleted; false otherwise