Servo listeners do not register themselves to servo

[NiteshKant]

RefCountingMonitor is used to register the servo monitors with servo, however, instead of registering the monitor instance with servo, RefCountingMonitor registers itself:

source

 public void onSubscribe() {
        if (subscriptionCount.incrementAndGet() == 0) {
            ServoUtils.registerObject(monitorId, this);
        }
    }

Instead, it should take the object to be registered with servo.