title: Android Studio Themes Don't Work in App
body: <p>I'm just getting started with Android development and have literally only been doing it for a few hours.</p>
  
  <p>Using the new Android Studio I've created a basic one-button app which creates a Toast text when I press it.  Whoopee.</p>
  
  <p>Problem is - when I select a "Theme" for my app layout page from the GUI, and select for example Halo (or any of them), it only changes my PREVIEW in the Android Studio. When I press "Run" (or export it to an apk), everything goes back to basic white style.</p>
  
  <p>It's as if it doesn't include the style/theme when building my app</p>