title: add JSONArray within a JSONObject
body: <p>I'm making an application to send notifications using OneSignal and must do a POST request in JSON format.</p>
  
  <p>To send notification to a user I have to use the <code>include_player_ids</code> argument which have to be an array because it is possible to send to multiple users the same notification (in my case I only send notification to one user).
  I use a JSONArray to create this array but when adding it to the JSONObject, there are extra quotes for the field <code>include_player_ids</code>.</p>
  
  <p>What I have:</p>
  
  <pre><code>{
    "headings": {"en":"my_title"},
    "contents": {"en":"my_text"},
    "include_player_ids": "[\"my-player-id\"]",
    "app_id":"my-app-id"
  }
  </code></pre>
  
  <p>As you can see, there is some quote around the array [ ].</p>
  
  <p>I guess it's what is making the response error from OneSignal :
  <code>errors":["include_player_ids must be an array"]</code></p>
  
  <p>What I want : </p>
  
  <pre><code>...
  "include_player_ids": ["my-player-id"] 
  ...
  </code></pre>
  
  <p>It is weird because adding JSONObject to JSONObject doesn't do this even though it is quite similar as you can see with the headings / contents fields</p>
  
  <p>My code :</p>
  
  <pre><code>import org.json.JSONException;
  import org.json.JSONObject;
  import org.json.alt.JSONArray;
  
  JSONObject headings = new JSONObject();
  JSONObject contents = new JSONObject();
  JSONArray player_id = new JSONArray();
  JSONObject notification = new JSONObject();
  try {
      notification.put("app_id", appId);
      notification.put("include_player_ids", player_id);
      player_id.put(idUser);
      headings.put("en", "my_title");
      contents.put("en", "my_text");
      notification.put("headings", headings);
      notification.put("contents", contents);             
  
  } catch (JSONException e) {
      System.out.println("JSONException :" + e.getMessage());
  }
  </code></pre>
  
  <p><code>idUser</code> is a String</p>
  
  <p>Thanks in advance for any help, </p>