title: Appbar scrolls the background Image up without decreasing the overall toolbar size
body: <p>I am trying to use the Material Design Library to create a toolbar that has a big background Image. The toolbar is followed by a ScrollView . On Scrolling , my expectation is that the toolbar will slowly get reduced to its min height while the rest of the ScrollView expands to fill up the area . Initially when the screen renders it looks like this <a href="https://i.stack.imgur.com/Y2Ix4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y2Ix4.png" alt="initialView"></a> . On scrolling the image shortens but the scrollview does not expand . It looks like this on scroll <a href="https://i.stack.imgur.com/2KWWN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2KWWN.png" alt="On Scroll"></a>
  Any idea why this might be happening ? </p>
  
  <pre><code>&lt;android.support.design.widget.CoordinatorLayout 
  android:id="@+id/draw_insets_frame_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent"&gt;&lt;android.support.v4.widget.NestedScrollView
     app:layout_behavior=
         "@string/appbar_scrolling_view_behavior"
     android:layout_width="match_parent"
     android:layout_height="match_parent"&gt;
     &lt;android.support.v7.widget.CardView
  
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:id="@+id/card_view_post"
         android:layout_margin="10dp"
         card_view:cardCornerRadius="@dimen/cardview_default_radius"
         card_view:cardUseCompatPadding="true"
         card_view:cardPreventCornerOverlap="true"
         android:elevation="@dimen/cardview_default_elevation"
         xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:card_view="http://schemas.android.com/apk/res-auto"
         style="@style/CardView.Light"&gt;
         &lt;!--Has other Views inside it --&gt;
     &lt;/android.support.v7.widget.CardView&gt;&lt;/android.support.v4.widget.NestedScrollView&gt;&lt;!--App bar starts --&gt;&lt;android.support.design.widget.AppBarLayout android:layout_width="match_parent"
      android:layout_height="wrap_content" android:minHeight="0dp"&gt;
      &lt;android.support.v7.widget.Toolbar android:id="@+id/toolbar1"
          app:layout_scrollFlags="scroll|enterAlways"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:minHeight="0dp" &gt;
  
      &lt;/android.support.v7.widget.Toolbar&gt;
  
  &lt;/android.support.design.widget.AppBarLayout&gt;
  </code></pre>
  
  <p></p>