title: Set background image to CollapsingToolbarLayout in android 6
body: <p>When I use <code>CollapsingToolbarLayout</code> in android version 5 or less it works perfectly fine but in android version 6 it doesn't show the image.<br>
  as follows:<br></p>
  
  <pre><code>&lt;android.support.design.widget.AppBarLayout
      android:id="@+id/app_bar"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:fitsSystemWindows="true"
      android:background="#FFFF"
      android:theme="@style/AppTheme.AppBarOverlay"&gt;
  
      &lt;android.support.design.widget.CollapsingToolbarLayout
          android:id="@+id/toolbar_layout"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:fitsSystemWindows="true"
          app:contentScrim="?attr/colorPrimary"
          app:layout_scrollFlags="scroll|exitUntilCollapsed"&gt;
  
          &lt;ImageView
              android:layout_width="match_parent"
              android:layout_height="@dimen/app_bar_height"
              android:scaleType="centerCrop"
              android:src="@drawable/image"
              /&gt;
      &lt;/android.support.design.widget.CollapsingToolbarLayout&gt;
      &lt;include layout="@layout/card_view"/&gt;
  &lt;/android.support.design.widget.AppBarLayout&gt;
  </code></pre>
  
  <p>in android 5 or less<br>
  <img src="https://i.stack.imgur.com/aVfPM.jpg" alt="enter image description here"></p>
  
  <p>in android 6<br>
  <img src="https://i.stack.imgur.com/fYs3F.jpg" alt="enter image description here"></p>