Array request body not showing up in Dev Portal

Google Cloud Apigee
1

I have created a yaml document where one of the definition (UserCreateRequest) has a property referring to array of other definition(PhoneNumber) as shown below .When i uploaded the swagger document in the dev portal , I do not see array of PhoneNumbers instead i see a json as

{
    "email": "",
    "password": "",
    "first_name": "",
    "last_name": "",
    "phone_numbers": [
        "PhoneNumber"
    ]
}

sample of Swagger :

"definitions": {
     "UserCreateRequest": {
            "type": "object",
            "required": [
                "email",
                "password",
            ],
            "properties": {
                "email": {
                    "type": "string",
                    "description": "The user's email address"
                },
                "password": {
                    "type": "string",
                    "description": "The user's password"
                },
                "first_name": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 50
                },
                "last_name": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 50
                },
                "phone_numbers": {
                    "type": "array",
                    "description": "The user's phone number",
                    "items": {
                        "$ref": "#/definitions/PhoneNumber"
                    }
                  },
            "description": "The information passed by a user used for enrollment."
        }
Where "PhoneNumber" is  another definition as below
"PhoneNumber": {
            "type": "object",
            "required": [
                "country_code",
                "is_primary",
                "is_sms_enabled",
                "number"
            ],
            "properties": {
                "number": {
                    "type": "string",
                    "minLength": 8,
                    "maxLength": 15
                },
                "is_sms_enabled": {
                    "type": "boolean",
                    "default": false
                },
                "is_primary": {
                    "type": "boolean",
                    "default": false
                },
                "country_code": {
                    "type": "string",
                    "description": "The country code",
                    "minLength": 1,
                    "maxLength": 3
                }
            },
            "description": "A user's phone number."
        }
}