title: No need to register base Activity class in the Manifest?
body: <p>I have my own base abstract class which extends <code>Activity</code> class. </p>
  
  <pre><code>public abstract class BaseActivity extends Activity {
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(getLayoutResourceId());
      }
  
      protected abstract int getLayoutResourceId();
  }
  
  public class Activity1 extends BaseActivity {
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          // do extra stuff 
      }
  
      @Override
      protected int getLayoutResourceId() {
          return R.layout.layout_for_activity1;
      }
  }
  </code></pre>
  
  <p>My base class <code>BaseActivity</code> is not registered in the <code>Manifest</code> file and I do not get any error. </p>
  
  <p>Is this a time bomb (not registering base class in Manifest) or this is the way it should be? Can someone explain why?</p>