title: Custom icon in Android toolbar
body: <p>I'm trying to use define a custom icon in the support Toolbar but the only icon shown is a left arrow... I tried to set it in the layout and programmatically but the result is the same.</p>
  
  <p>Here is my Activity </p>
  
  <pre><code>public class MainActivity extends ActionBarActivity {
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      Toolbar toolbar = (Toolbar) findViewById(R.id.my_toolbar);
      toolbar.setNavigationIcon(R.drawable.ic_launcher);
      toolbar.setTitle("");
      setSupportActionBar(toolbar);
  }
  </code></pre>
  
  <p>And my toolbar layout</p>
  
  <pre><code>&lt;android.support.v7.widget.Toolbar
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:id="@+id/my_toolbar"
      android:layout_height="wrap_content"
      android:layout_width="match_parent"
      app:navigationIcon="@drawable/ic_action_bar"
      android:minHeight="@dimen/action_bar_size"
      android:background="?attr/colorPrimary"
      app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
      app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
      /&gt;
  </code></pre>