title: Navigation Drawer Icon not visible with custom action bar?
body: <p>I am trying to use navigation drawer with custom action bar. My action bar does not contain any menu.<br>
  I see that the Navigation Drawer icon, is not visible on the action bar when the drawer is closed. Even though I have given the drawer icon in the <code>ActionbarToggle</code> implementation. The drawer icon appears when the <code>navigation drawer</code> is open, but disappears when the <code>navigation drawer</code> closes.
  <br></p>
  
  <p><strong>Activty</strong><br></p>
  
  <pre><code> public void setCustomActionBar() {
          ActionBar actionBar = getActionBar();
          actionBar.setCustomView(R.layout.action_bar);
  }
  </code></pre>
  
  <p><strong>NavigationDrawer Fragment</strong><br></p>
  
  <pre><code>getActivity(),                    /* host Activity */
          mDrawerLayout,                    /* DrawerLayout object */
          R.drawable.drawer,             /* nav drawer image to replace 'Up' caret */
          R.string.navigation_drawer_open,  /* "open drawer" description for accessibility */
          R.string.navigation_drawer_close  /* "close drawer" description for accessibility */
  ) {...
  </code></pre>
  
  <p>As you can see I have provided the drawer icon above. 
  Why is this happening and what is the solution to this?</p>