title: Strange whitespace on Android Toolbar
body: <p>I'm working on putting a <code>Toolbar</code> to screen bottom. After I hide the toolbar title, the title still occupies spaces. </p>
  
  <p><a href="https://i.stack.imgur.com/gTNn0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gTNn0.png" alt="Screenshot"></a></p>
  
  <p><strong>My question is:</strong> how can I remove the space? </p>
  
  <hr>
  
  <p><strong>styles.xml</strong></p>
  
  <pre><code>&lt;resources&gt;
      &lt;!-- Base application theme. --&gt;
      &lt;style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"&gt;
          &lt;!-- Customize your theme here. --&gt;
          &lt;item name="colorPrimary"&gt;@color/colorPrimary&lt;/item&gt;
          &lt;item name="colorPrimaryDark"&gt;@color/colorPrimaryDark&lt;/item&gt;
          &lt;item name="colorAccent"&gt;@color/colorAccent&lt;/item&gt;
          &lt;item name="windowActionBar"&gt;false&lt;/item&gt;
          &lt;item name="windowNoTitle"&gt;true&lt;/item&gt;
      &lt;/style&gt;
  &lt;/resources&gt;
  </code></pre>
  
  <p>In my Activity's <code>onCreate()</code>:</p>
  
  <pre><code>toolbar = (Toolbar)findViewById(R.id.bar_bottom);
  setSupportActionBar(toolbar);
  getSupportActionBar().setSubtitle("");
  getSupportActionBar().setDisplayShowTitleEnabled(false);
  </code></pre>
  
  <p>and in same activity's <code>onCreateOptionsMenu</code> and <code>onOptionsItemSelected</code>:</p>
  
  <pre><code>@Override
  public boolean onCreateOptionsMenu(Menu menu) {
      getMenuInflater().inflate(R.menu.menu_bar_bottom, menu);
      return true;
  }
  
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
      return super.onOptionsItemSelected(item);
  }
  </code></pre>
  
  <p>and in my layout:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingTop="@dimen/activity_vertical_margin"
      tools:context=".WelcomeActivity"&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:orientation="vertical"&gt;
          &lt;TextView
              android:id="@+id/lbl_test"
              android:layout_width="match_parent"
              android:layout_height="20sp"
              android:text=""
              /&gt;
      &lt;/LinearLayout&gt;
      &lt;android.support.v7.widget.Toolbar
          android:id="@+id/bar_bottom"
          android:layout_height="wrap_content"
          android:layout_width="match_parent"
          android:background="?attr/colorPrimary"
          android:layout_alignParentBottom="true"
           /&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>and the Menu:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      tools:context=".WelcomeActivity"&gt;
      &lt;item
          android:id="@+id/btn_1"
          android:orderInCategory="100"
          android:title="Button 1"
          app:showAsAction="always" /&gt;
      &lt;item
          android:id="@+id/btn_2"
          android:orderInCategory="200"
          android:title="Button 2"
          app:showAsAction="always" /&gt;
      &lt;item
          android:id="@+id/btn_3"
          android:orderInCategory="300"
          android:title="Button 3"
          app:showAsAction="always" /&gt;
      &lt;item
          android:id="@+id/btn_4"
          android:orderInCategory="400"
          android:title="Button 4"
          app:showAsAction="always" /&gt;
  &lt;/menu&gt;
  </code></pre>