title: Strange transparent CardView bg
body: <p>I have a problem with transparent CardView. It happens when i set CornerRadius attribute to card, without this attribute everything is ok. It looks like this(marked red):<a href="https://i.stack.imgur.com/ARfpx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ARfpx.png" alt="enter image description here"></a></p>
  
  <p>Code:</p>
  
  <pre><code>&lt;android.support.v7.widget.CardView &lt;android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:card_view="http://schemas.android.com/apk/res-auto"
  android:id="@+id/item"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal"
  card_view:cardCornerRadius="@dimen/some_dimen_here"
  card_view:cardUseCompatPadding="true"
  card_view:cardBackgroundColor="@android:color/transparent"&gt;
  </code></pre>
  
  <p>How it cane be fixed? any ideas?</p>