title: AppCompatActivity as a dialog without title
body: <p>I have an <code>Activity</code> inherited from <code>AppCompactActivity</code>. in manifest for activity set theme:</p>
  
  <pre><code>&lt;style name="Theme.custom" parent="Theme.AppCompat.Light.Dialog"&gt;
      &lt;item name="android:windowNoTitle"&gt;true&lt;/item&gt;
      &lt;item name="colorPrimary"&gt;@color/primary&lt;/item&gt;
      &lt;item name="colorPrimaryDark"&gt;@color/primary_dark&lt;/item&gt;
      &lt;item name="colorAccent"&gt;@color/accent&lt;/item&gt;
      &lt;item name="colorButtonNormal"&gt;@color/accent&lt;/item&gt;
      &lt;item name="android:buttonStyle"&gt;@style/ButtonStyle&lt;/item&gt;
  &lt;/style&gt;
  </code></pre>
  
  <p>When I run activity, it shows as a dialog, but title is shown! i try <code>supportRequestWindowFeature(Window.FEATURE_NO_TITLE)</code> and  <code>RequestWindowFeature(Window.FEATURE_NO_TITLE)</code> but title still displayed. Please let me know, What is wrong?</p>
  
  <hr>
  
  <p>Edit</p>
  
  <p>I solve it, only change <code>android:windowNoTitle</code> to  <code>windowNoTitle</code>! because i am use AppCompactActvity!</p>