No need of isAvailable when doing registerNetworkCallback

Due this two time connectivity status got reported back. Can you tell me why do you have the below part in registerNetoworkCallback 

`if (isAvailable(context)) {
                context.sendBroadcast(getNetworkAvailabilityIntent(true));
            } else {
                context.sendBroadcast(getNetworkAvailabilityIntent(false));
            }`

I hope this wont be required by default.
