title: Toolbar and Tabs not appearing up with ViewPager
body: <p>I am getting <code>Toolbar and Tabs</code>, If I would not use <code>ViewPager</code> :</p>
  
  <pre><code>&lt;android.support.v4.view.ViewPager
      android:id="@+id/viewpager"
      android:layout_width="match_parent"
      android:layout_height="match_parent" /&gt;
  </code></pre>
  
  <p>But when I use ViewPager, I am <strong>not getting</strong> Toolbar and Tabs</p>
  
  <pre><code>&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:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;android.support.design.widget.AppBarLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:theme="@style/ThemeOverlay.AppCompat.Dark"&gt;
  
          &lt;android.support.v7.widget.Toolbar
              android:id="@+id/toolbar"
              android:layout_width="match_parent"
              android:layout_height="?attr/actionBarSize"
              android:background="?attr/colorPrimary"
              app:layout_scrollFlags="scroll|enterAlways" /&gt;
  
          &lt;android.support.design.widget.TabLayout
              android:id="@+id/tablayout"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              app:tabGravity="fill"
              app:tabMode="fixed" /&gt;
  
      &lt;/android.support.design.widget.AppBarLayout&gt;
  
      &lt;android.support.v4.view.ViewPager
          android:id="@+id/viewpager"
          android:layout_width="match_parent"
          android:layout_height="match_parent" /&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>