title: Set button text to question mark
body: <p>I need to set a button's text to just <code>?</code>.<br>
  I'm happy to do it via Java, but would rather do it via the XML.<br>
  Is it possible? </p>
  
  <p>I've tried <code>android:text="?"</code>  and <code>android:text="&amp;#63;"</code> but it did not work.<br>
  Then I set one of the string resources to <code>?</code>, and when that did not work I set it to <code>&amp;#63;</code>referenced that but it doesn't work!</p>
  
  <p>How do I set the button caption to <kbd>?</kbd> using XML?</p>