title: How to make bottom sheet push toolbar out when expanding and pull it back in when collapsed?
body: <p>I want the toolbar to be pushed upwards and out of the view when bottom sheet is expanding and be pulled back in when it gets collapsed. All the examples I see are other views merging into the toolbar or snapping to toolbar to top but none of them hide the toolbar. How does one do that?</p>
  
  <pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.design.widget.CoordinatorLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:id="@+id/activity_map"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fitsSystemWindows="true"
      &gt;
  
  
    &lt;FrameLayout
        android:id="@+id/mainContentContainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/red"
        /&gt;
  
  
    &lt;android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true"
        &gt;
  
      &lt;FrameLayout
          android:id="@+id/topContentContainer"
          android:layout_width="match_parent"
          android:layout_height="50dp"
          android:background="@color/blue"
          app:layout_scrollFlags="scroll|enterAlways|snap"
          /&gt;
  
    &lt;/android.support.design.widget.AppBarLayout&gt;
  
    &lt;FrameLayout
        android:id="@+id/categoriesSelectionContainer"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:background="@color/green"
        app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
        &gt;
  
      &lt;android.support.v4.widget.NestedScrollView
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          app:layout_behavior="android.support.design.widget.AppBarLayout.ScrollingViewBehavior"
          &gt;
  
        &lt;TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum."
            /&gt;
  
      &lt;/android.support.v4.widget.NestedScrollView&gt;
    &lt;/FrameLayout&gt;
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>