Serialized class to google games services cloud save

I am just now incorporating google play game services into my project. I already have a system in place for saving local snapshots. I am now trying to save these snapshot classes to the cloud. Here is an example class to illustrate my method:

  using UnityEngine;    
     using UnityEngine.UI;
     using System.IO;
     using System.Runtime.Serialization.Formatters.Binary;
     using GooglePlayGames;
     using UnityEngine.SocialPlatforms;
     
     
     public class GMan : MonoBehaviour {
     
         public int score;
         public Text text;
         public Text connected;
         public bool IsConnectedToGoogleServices;
     
     
         public static GMan Instance;
     
         void Awake()
         {
             Instance = this;
             PlayGamesPlatform.Activate();
             PlayGamesPlatform.DebugLogEnabled = true;
             
     
         }
     
         // Use this for initialization
         void Start () {
             ConnectToGoogleServices();
             Load();
     
         
         }
     
         public void AuthTest()
         {
             Social.localUser.Authenticate((bool success) =>
             {
                 IsConnectedToGoogleServices = success;
             });
         }
     
         public bool ConnectToGoogleServices()
         {
             if (!IsConnectedToGoogleServices)
             {
     
                 Social.localUser.Authenticate((bool success) =>
                 {
                     IsConnectedToGoogleServices = success;
                 });
             }
     
             return IsConnectedToGoogleServices;
         }
     
         void OnApplicationFocus(bool focusStatus)
         {
     
             if (focusStatus == false)
             {
                 
                 Instance.Save();
             }
             
         }
     
         // Update is called once per frame
         void Update () {
             text.text = score.ToString();
             string str;
     
             if (IsConnectedToGoogleServices)
             {
                 str = "true";
             }else
             {
                 str = "false";
             }
             
             connected.text = "Connected: " + str;
         }
     
         public void Tick()
         {
             score++;
         }
     
         public void ToAchieve()
         {
     
             Social.ShowAchievementsUI();
         }
     
         public void Save()
         {
             print("Saving Game");
             BinaryFormatter bf = new BinaryFormatter();
            
             FileStream file = File.Create(Application.persistentDataPath + "/SaveData.dat");
     
             SaveData saveData = new SaveData();
     
             saveData.score = Instance.score;
             bf.Serialize(file, saveData);
             file.Close();
         }
     
         public void Load()
         {
             if (File.Exists(Application.persistentDataPath + "/SaveData.dat"))
             {
                 BinaryFormatter bf = new BinaryFormatter();
                 FileStream file = File.Open(Application.persistentDataPath + "/SaveData.Dat", FileMode.Open);
                 SaveData saveData = (SaveData)bf.Deserialize(file);
                 file.Close();
     
                 Instance.score = saveData.score;
             }
         }
     }
     
     
     [System.Serializable]
     public class SaveData
     {
         public int score;
     }

Play game services takes a byte[] as the payload param. How would I convert the instance of saveData to byte[] for saving. How would I turn a byte[] into an instance of saveData for loading?

Is a serialized class just a byte[]?