title: Center SelectBox text in libgdx using scene2d
body: <p>I have the following SelectBox:</p>
  
  <pre><code>//Select Box Style
  SelectBox.SelectBoxStyle boxStyle = new SelectBox.SelectBoxStyle();
  boxStyle.fontColor = settingsFontColor;
  boxStyle.background = new SpriteDrawable(rectangle);
  boxStyle.font = skin.getFont("default");
  boxStyle.scrollStyle = sps;
  boxStyle.scrollStyle.background = new SpriteDrawable(rectangle);
  boxStyle.listStyle = new List.ListStyle();
  boxStyle.listStyle.font = skin.getFont("default");
  boxStyle.listStyle.fontColorSelected = selectBoxSelectedColor;
  boxStyle.listStyle.fontColorUnselected = selectBoxUnselectedColor;
  boxStyle.listStyle.selection = new SpriteDrawable(selectBoxOption);
  boxStyle.listStyle.background = new SpriteDrawable(selectBoxOption);
  
  //SelectBox
  String[] ballSpeeds = new String[]{"Slow", "Medium", "Fast", "Fastest"};
  final SelectBox&lt;String&gt; ballspeedbox = new SelectBox&lt;String&gt;(boxStyle);
  ballspeedbox.setItems(ballSpeeds);
  </code></pre>
  
  <p>By default the text is left aligned (Slow, Medium, Fast, Fastest). How do I center the text?</p>