title: Passing "null" as DialogInterface.OnClickLIstener legit?
body: <p>Just a quick question: I just found out that </p>
  
  <pre><code>new AlertDialog.Builder(this)
  .setTitle("Hi")
  .setMessage("Some text. Did you read it?")
  .setPositiveButton("Yes", new DialogInterface.OnClickListener() {               
      @Override
      public void onClick(DialogInterface dialog, int which) {
          // do something
      }
  })
  .setNegativeButton("No, I'm too lazy", null)
  .show();
  </code></pre>
  
  <p>works well on my device. Passing a null as DialogInterface.OnClickListener simply dismisses the dialog. I wanted to ask, if this is legit or might cause problems for example on older devices / Android versions? I did not find anything in the documentation. </p>
  
  <p>I never did it that way until now, but it saves some code and makes sense in my opinion. Until now, I always created a OnClickListener to dismiss the dialog. Kinda unnecessary it seems.</p>