Custom services can't be discovered on certain devices

[sammy00747]

@sandeepmistry first of all, great work with bleno!

I am trying to create a custom service, which has a single characteristic , to test the working of bleno:

`// Using the bleno module
var bleno = require('bleno');

// Once bleno starts, begin advertising our BLE address
bleno.on('stateChange', function(state) {
console.log('State change: ' + state);
if (state === 'poweredOn') {
bleno.startAdvertising('MyDevice',['12ab']);
} else {
bleno.stopAdvertising();
}
});

// Notify the console that we've accepted a connection
bleno.on('accept', function(clientAddress) {
console.log("Accepted connection from address: " + clientAddress);
});

// Notify the console that we have disconnected from a client
bleno.on('disconnect', function(clientAddress) {
console.log("Disconnected from address: " + clientAddress);
});

// When we begin advertising, create a new service and characteristic
bleno.on('advertisingStart', function(error) {
if (error) {
console.log("Advertising start error:" + error);
} else {
console.log("Advertising start success");
bleno.setServices([

        // Define a new service
        new bleno.PrimaryService({
            uuid : '12ab',
            characteristics : [
                
                // Define a new characteristic within that service
                new bleno.Characteristic({
                    value : null,
                    uuid : '34cd',
                    properties : ['notify', 'read', 'write'],
                    
                    // If the client subscribes, we send out a message every 1 second
                    onSubscribe : function(maxValueSize, updateValueCallback) {
                        console.log("Device subscribed");
                        this.intervalId = setInterval(function() {
                            console.log("Sending: Hi!");
                            updateValueCallback(new Buffer("Hi!"));
                        }, 1000);
                    },
                    
                    // If the client unsubscribes, we stop broadcasting the message
                    onUnsubscribe : function() {
                        console.log("Device unsubscribed");
                        clearInterval(this.intervalId);
                    },
                    
                    // Send a message back to the client with the characteristic's value
                    onReadRequest : function(offset, callback) {
                        console.log("Read request received");
                        callback(this.RESULT_SUCCESS, new Buffer("Echo: " + 
                                (this.value ? this.value.toString("utf-8") : "")));
                    },
                    
                    // Accept a new value for the characterstic's value
                    onWriteRequest : function(data, offset, withoutResponse, callback) {
                        this.value = data;
                        console.log('Write request: value = ' + this.value.toString("utf-8"));
                        callback(this.RESULT_SUCCESS);
                    }

                })
                
            ]
        })
    ]);
}

});`

While this code works just fine with Honor 9N and MI Note 5, it seems to have issues with Samsung S7 Edge - this particular device can't discover the custom service created.

Environment - ubuntu 18.04 LTS.