title: How can I remove android actionbar Shadow
body: <p>I'm using Android Studio for programming. Target SDK is 23 and Minimum SDK is 15</p>
  
  <p>I'm trying to remove the shadow between my actionbar and my sliding tab layout. But I'm not able to.</p>
  
  <p>Note : The shadow is only visible in Android 5 and upper.</p>
  
  <p>I have used <code>&lt;item name="elevation"&gt;0dp&lt;/item&gt;</code> and <code>getSupportActionBar().setElevation(0);</code>
  But still it doesn't work...</p>
  
  <p><a href="https://i.stack.imgur.com/TYnOv.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/TYnOv.jpg" alt="enter image description here"></a></p>
  
  <p><strong>My Style.xml</strong></p>
  
  <pre><code>&lt;resources&gt;
  
  &lt;!-- Base application theme. --&gt;
  &lt;style name="AppTheme" parent="Theme.AppCompat.Light"&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;/style&gt;
  
  
  
  &lt;style name="AppTheme.NoActionBar"&gt;
      &lt;item name="windowActionBar"&gt;false&lt;/item&gt;
      &lt;item name="windowNoTitle"&gt;true&lt;/item&gt;
  &lt;/style&gt;
  
  
  
  &lt;style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" /&gt;
  &lt;style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light"&gt;
      &lt;item name="elevation"&gt;0dp&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p></p>
  
  <p><strong>My Style V21</strong></p>
  
  <pre><code>&lt;resources&gt;&gt;
  &lt;style name="AppTheme.NoActionBar"&gt;
      &lt;item name="windowActionBar"&gt;false&lt;/item&gt;
      &lt;item name="windowNoTitle"&gt;true&lt;/item&gt;
      &lt;item name="android:windowDrawsSystemBarBackgrounds"&gt;true&lt;/item&gt;
      &lt;item name="android:statusBarColor"&gt;@android:color/transparent&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p></p>
  
  <p><strong>My MainActivity.java onCreateCode:</strong></p>
  
  <pre><code> @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
      setSupportActionBar(toolbar);
  
      getSupportActionBar().setElevation(0);
  </code></pre>
  
  <p>....</p>