title: How to use device default theme for app?
body: <p>I have an app that I want to develop for Android 2.1, 2.2, 2.3.3, 3.0/3.1 and 4.0.x. Between those API levels, there are about 3 different types of Themes. The latest 4.0.x theme is Holo. </p>
  
  <p>Anyways, I want my app to use the default Android theme for whatever device it's on. If it's on a 4.0.x device, I want it to use Holo. If it's on 2.3.3 I want it to use the theme from that version of Android. etc...</p>
  
  <p>Is there a simple way to approach this? I noticed that with 4.0, they added a <code>Theme.DeviceDefault</code> theme that you can use, but this doesn't help me for older API levels. What is the best approach to this?</p>