Handle RemoteMessage object using data class in Kotlin

Question

I am using firebase in order to receive push notification from the server. The push notification I receive from the server is in Json format. For example:

{
    "data": {
        "body": "This is test notification message!",
        "date": "2021-04-01 08:50",
        "title": "test"
    },
    "registration_ids": [
        "some fcm token"
    ]
}

I would like to parse this object using data class Here is my class:

data class ServerRemoteMessage (
    @SerializedName(DATA) val data : Data
)

data class Data (
    @SerializedName(TITLE) val title : String,
    @SerializedName(BODY) val body : String
)

Here is the way I'm trying to handle it, without success:

class PushMessagingService : FirebaseMessagingService() {

    val TAG: String
        get() = "PushMessagingService"

    override fun onMessageReceived(remoteMessage: RemoteMessage) {
        handleRemoteMessageData(remoteMessage)
    }

    override fun onNewToken(token: String) {
        Log.d(TAG, "token $token")
        // TODO send token to the serve
    }

    private fun handleRemoteMessageData(remoteMessage: RemoteMessage) {
        val remoteMessage = Gson().fromJson(Gson().toJson(remoteMessage.data), ServerRemoteMessage::class.java)
        val title = remoteMessage.data.title
        val body = remoteMessage.data.body
        NotificationUtils.showNotification(this, title, body,
            R.drawable.ic_notification, R.color.blue,
            getString(R.string.app_name))
    }
}