FCM Notification in iOS doesn't play sound when received
<p>I am using Firebase push notifications in my iOS Application. Although I am able to send the notification by sending below payload, it doesn't play a sound when received. </p>

<pre><code>{
    "to": "myToken",
    "notification": {
        "body": "test",
        "title": "test"
    },
    "priority": "high"
    "sound": "default"
}
</code></pre>

<p>If I send the test message from console, it works well and plays notification sound. <br> <strong>Note</strong>: </p>

<ol>
<li>My Authorization code is correct</li>
<li>I am sending http request to <code>https://fcm.googleapis.com/fcm/send</code></li>
<li>I have tested it on IPhone 4 , IPhone 6 and IPhone 6S, All recieve
notifications without sound</li>
</ol>