title: Is it possible to change up button icon in Navigation Component?
body: <p>I would like to change up button icon in ActionBar that is working with Navigation Component. I've tried several options like:</p>
  
  <pre><code>supportActionBar?.setHomeAsUpIndicator(R.drawable.ic_arrow_left_blue_24dp)
  </code></pre>
  
  <p>in <code>MainAcitivty</code> or </p>
  
  <pre><code>app:navigationIcon="@drawable/ic_arrow_left_blue_24dp"
  </code></pre>
  
  <p>in <code>Toolbar</code> .xml file and nothing seems to work.</p>
  
  <p>I have a pretty standard setup with </p>
  
  <pre><code>setSupportActionBar(appToolbar.toolbar)
  setupActionBarWithNavController(this, navController)
  </code></pre>
  
  <p>called in <code>MainActivity:onCreate</code> method.</p>
  
  <p>I would expect that </p>
  
  <pre><code>supportActionBar?.setHomeAsUpIndicator(R.drawable.ic_arrow_left_blue_24dp)
  </code></pre>
  
  <p>would work, because for example disabling title for <code>ActionBar</code> by calling:</p>
  
  <pre><code>supportActionBar?.setDisplayShowTitleEnabled(false)
  </code></pre>
  
  <p>works as expected and title is not set to <code>Fragment</code> name while navigating. </p>
  
  <p>What's more, I investigated a little bit and in <code>ActionBarOnDestinationChangedListener</code> there is a call to <code>setNavigationIcon</code> which is setting an icon to <code>DrawerArrowDrawable</code>, which is a little bit weird since I'm not using <code>Drawer</code> in my setup. </p>
  
  <p>Also changing to:</p>
  
  <pre><code>setupWithNavController(toolbar, navController)
  </code></pre>
  
  <p>is not working because <code>ToolbarOnDestinationChangedListener</code> also using the same <code>DrawerArrowDrawable</code>.</p>