title: How to configure the Drawer Navigation button when not using the start as the top-level navigation?
body: <p>I'm using the navigation graph to navigate and have a start screen (splash fragment) as the first fragment that is shown. The issue is that when I go to the main fragment/screen the top navigation button shows back instead of the drawer icon.
  How can we get control over this? What are some options. How can I change the start destination? (if possible)</p>
  <blockquote>
  <p>When the user is at a top-level destination, the Navigation button
  becomes a drawer icon  if the destination uses a DrawerLayout. If the
  destination doesn't use a DrawerLayout, the Navigation button is
  hidden. When the user is on any other destination, the Navigation
  button appears as an Up button . <strong>To configure the Navigation button
  using only the start destination as the top-level destination, create
  an AppBarConfiguration object, and pass in the corresponding
  navigation graph, as shown below:</strong></p>
  </blockquote>
  <p><strong>Example Code</strong></p>
  <p>My issue is that the back button is still present when navigating to next_fragment. It should show the menu/hamburger icon.</p>
  <pre><code>class MainActivity : AppCompatActivity() {
  
  private lateinit var drawerLayout: DrawerLayout
  private lateinit var appBarConfiguration : AppBarConfiguration
  
  override fun onCreate(savedInstanceState: Bundle?) {
  
      super.onCreate(savedInstanceState)
  
      val binding = DataBindingUtil.setContentView&lt;ActivityMainBinding&gt;(this, R.layout.activity_main)
      drawerLayout = binding.drawerLayout
  
      val navController = this.findNavController(R.id.mainNavigationHostFragment)
      NavigationUI.setupActionBarWithNavController(this, navController)
  
      appBarConfiguration = AppBarConfiguration(setOf(R.id.nextFragment), drawerLayout) 
      NavigationUI.setupWithNavController(binding.mainNavigationDrawerView, navController)
  
      val navigationHeader = binding.mainNavigationDrawerView.getHeaderView(0)
      val iconButton = navigationHeader.findViewById&lt;ImageButton&gt;(R.id.main_nav_icon_button)
      
  
  }
  
  override fun onSupportNavigateUp(): Boolean {
  
      val navController = this.findNavController(R.id.mainNavigationHostFragment)
      return NavigationUI.navigateUp(navController, appBarConfiguration)
  }
  </code></pre>
  <p>}</p>