Ensure that the selected script CriticalPushPayloadBuilder is in ITSM Mobile Agent application scope.

var CriticalPushPayloadBuilder = Class.create();
CriticalPushPayloadBuilder.prototype = {
    initialize: function(currentGR, json, attributes) {
        this.currentGR = currentGR;
        this.json = json;
        this.attributes = attributes;
    },
    buildJSON: function() {
        if (this.attributes == null || this.attributes.isCritical == null || !(this.attributes.isCritical == "true"))
            return this.json;
        this.json["sncGoogleKeys"] = {
            "android": {
                "priority": "high"
            },
            "priority": "high"
        };
        this.json["aps"]["sound"] = {
            "critical": 1,
            "name": "NotificationAlert-9-Short.caf",
            "volume": 1
        };
        return this.json;
    },
    type: 'CriticalPushPayloadBuilder'
};