title: Add gradient to imageview
body: <p>I want to add a gradient on the bottom of my image . Something like this :</p>
  
  <p><img src="https://i.stack.imgur.com/7soSW.jpg" alt="enter image description here"></p>
  
  <p>I tried something like this but I only get the gradient no image..</p>
  
  <pre><code>    &lt;ImageView
      android:id="@+id/trendingImageView"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:background="@drawable/trend_donald_sterling"
      android:src="@drawable/trending_gradient_shape"
    /&gt;
  </code></pre>
  
  <p>trending_gradient_shape:</p>
  
  <pre><code>&lt;shape xmlns:android="http://schemas.android.com/apk/res/android"
         android:shape="rectangle" &gt;
  
      &lt;gradient
          android:angle="90"
          android:endColor="@android:color/darker_gray"
          android:startColor="@android:color/darker_gray" /&gt;
  
      &lt;corners android:radius="0dp" /&gt;
  
  &lt;/shape&gt;
  </code></pre>