title: How to setSupportActionBar in a view that extends LifecycleActivity
body: <p>I had an Activity that extended AppCompactActivity, and in <code>onCreate</code> method I setted the <code>Toolbar</code> using <code>setSupportActionBar</code> method in the usual way:</p>
  
  <pre><code>public class StepMasterActivity extends AppCompatActivity{
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_step_master);
          Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);`
      }
  }
  </code></pre>
  
  <p>But now I have a <a href="https://developer.android.com/topic/libraries/architecture/viewmodel.html#the_lifecycle_of_a_viewmodel" rel="noreferrer">ViewModel</a> component and to share data between fragments that are the children of this activity and manages lifecycles I have to get this component in Activity and so I make this extend LifecycleActivity. </p>
  
  <pre><code>public class StepMasterActivity extends LifecycleActivity {
  
      @Override
      public class StepMasterActivity extends LifecycleActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_step_master);
          // setToolbar();
          SharedViewModel sharedViewModel = ViewModelProviders.of(this).get(SharedViewModel.class);
      }
  }
  </code></pre>
  
  <p>But I noticed that LifecycleActivity has nothing to do with AppCompatActivity neither FragmentActivity does.</p>
  
  <pre><code>public class LifecycleActivity extends FragmentActivity implements LifecycleRegistryOwner {
      private final LifecycleRegistry mRegistry = new LifecycleRegistry(this);
  
      public LifecycleActivity() {
      }
  
      public LifecycleRegistry getLifecycle() {
          return this.mRegistry;
      }
  }
  </code></pre>
  
  <p>Am I doing something wrong? </p>