title: Toolbar navigation icon never set
body: <p>I'm trying the new Toolbar component and having some trouble with the navigation icon.
  I want to implement a custom icon for back navigation :</p>
  <p>In my manifest i set a parent to my activity :</p>
  <pre><code>&lt;activity android:name=&quot;.CardsActivity&quot; android:parentActivityName=&quot;.MainActivity&quot;&gt;
      &lt;!-- Parent activity meta-data to support API level 7+ --&gt;
      &lt;meta-data
          android:name=&quot;android.support.PARENT_ACTIVITY&quot;
          android:value=&quot;.MainActivity&quot; /&gt;
  &lt;/activity&gt;
  </code></pre>
  <p>I declare the toolbar like this :</p>
  <pre><code>&lt;RelativeLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
      xmlns:tools=&quot;http://schemas.android.com/tools&quot;
      android:layout_width=&quot;match_parent&quot;
      android:layout_height=&quot;match_parent&quot;
      android:paddingBottom=&quot;@dimen/activity_vertical_margin&quot;
      tools:context=&quot;com.example.lollitest.MainActivity&quot; &gt;
      
      &lt;android.support.v7.widget.Toolbar
          android:id=&quot;@+id/my_awesome_toolbar&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:layout_width=&quot;match_parent&quot;
          android:minHeight=&quot;?attr/actionBarSize&quot;
          android:layout_marginBottom=&quot;10dp&quot;
          android:background=&quot;?attr/colorPrimary&quot; /&gt;
  
      &lt;TextView
          android:layout_width=&quot;wrap_content&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:layout_below=&quot;@+id/my_awesome_toolbar&quot;
          android:text=&quot;@string/hello_world&quot; /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  <p>Then in my activity i configure the Toolbar like this :</p>
  <pre><code>Toolbar toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar);
  toolbar.setNavigationIcon(R.drawable.ic_good);
  toolbar.setTitle(&quot;Title&quot;);
  toolbar.setSubtitle(&quot;Sub&quot;);
  toolbar.setLogo(R.drawable.ic_launcher);
  setSupportActionBar(toolbar);
  </code></pre>
  <p>Which giving me :
  <img src="https://i.stack.imgur.com/Oul74.png" alt="Toolbar with back button" /></p>
  <p>The back icon <strong>is not</strong> the one i set with <code>setNavigationIcon()</code> ! Whatever drawable i give to the method the navigation icon is always the back arrow.</p>
  <p>I have tried to remove the parent association in the manifest but the only effect is (obviously) to prevent the button to go back.</p>
  <p>On contrary if i want the default back arrow icon and don't call <code>setNavigationIcon()</code> i don't have any icon at all.</p>
  <p><strong>What is the correct way to handle the navigation icon in toolbar (custom and default) ?</strong></p>
  <p>NOte : i'm running my test on Android 4.4</p>