title: Set orientation fixed for all activities
body: <p>I know there are two ways to set an <code>Activity</code>'s orientation to landscape, either programmatically</p>
  
  <pre><code>setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
  </code></pre>
  
  <p>or in the Manifest:</p>
  
  <pre><code>android:orientation="landscape"
  </code></pre>
  
  <p>Currently, I use the first one in a superclass, because I have many (child) activities that I all want to be always in landscape. However, this make 
  <code>onCreate</code> being called twice, which leads to other issues. When using the Manifest-route, I have to apply it to all activities separately, which will undoubtedly lead to one being missed out in the future (not to mention all the code copying).</p>
  
  <p>Is there a way to apply <code>android:orientation="landscape"</code> to all activities in my app?</p>