title: Android - toolbar at bottom - how to show a border line at the top
body: <p>For some screens I use the "android.support.v7.widget.Toolbar" as an <strong>bottom toolbar</strong>. Works great. </p>
  
  <p>I would like to show a thin border at the top. How to create that border? 
  Below this border (line) the menu items are shown normally / horizontally. </p>
  
  <p>The toolbar could be as simple as this: </p>
  
  <pre><code>&lt;android.support.v7.widget.Toolbar
      android:id="@+id/toolbar_bottom"
      android:layout_height="wrap_content"
      android:layout_width="match_parent"
      android:background="@color/white"
      android:layout_alignParentBottom="true"
      android:minHeight="?attr/actionBarSize"&gt;
  &lt;/android.support.v7.widget.Toolbar&gt;
  </code></pre>
  
  <p>This border should be configurable as part of the toolbar, because on some actions the bottom toolbar is made invisible (and visible again). </p>