title: RecyclerView does not expand its height when an item is added on adapter
body: <p>I have a layout containing a <code>RecyclerView</code> and a layout for handling showing more items. When one or more items are received from hitting the <em>"Show more"</em> button the adapter is notified and the items are added on the RecyclerView. <strong>But</strong> the problem is, that the RecyclerView's <strong>height</strong> after an item has been added is not expanded. </p>
  
  <p>This layout is part of a fragment contained in a <code>ViewPager</code> under a <code>CollapsingToolbarLayout</code>.</p>
  
  <p>The structure of the fragment's layout:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:background="#f5f5f5"&gt;
  
  &lt;com.github.rahatarmanahmed.cpv.CircularProgressView
      android:id="@+id/progress_view"
      android:layout_width="45dp"
      android:layout_height="45dp"
      android:layout_gravity="center_horizontal"
      android:layout_marginTop="40dp"
      app:cpv_animAutostart="true"
      app:cpv_indeterminate="true"
      app:cpv_thickness="4dp"/&gt;
  
  &lt;LinearLayout
      android:id="@+id/list_container"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:orientation="vertical"&gt;
  
      &lt;android.support.v7.widget.RecyclerView
          android:id="@+id/reviews_list"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"/&gt;
  
      &lt;FrameLayout
          android:id="@+id/show_more_container"
          android:layout_width="match_parent"
          android:layout_height="50dp"
          android:background="#eee"&gt;
  
          &lt;TextView
              android:id="@+id/show_more_text"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_gravity="center"
              android:text="Show More"
              android:textSize="15sp"
              android:textColor="@color/colorPrimary"/&gt;
  
          &lt;com.github.rahatarmanahmed.cpv.CircularProgressView
              android:id="@+id/show_more_progress_view"
              android:layout_width="30dp"
              android:layout_height="30dp"
              android:layout_gravity="center"
              android:visibility="invisible"
              app:cpv_animAutostart="true"
              app:cpv_indeterminate="true"
              app:cpv_thickness="3dp"/&gt;
  
      &lt;/FrameLayout&gt;
  
  &lt;/LinearLayout&gt;
  
  &lt;/FrameLayout&gt;
  </code></pre>
  
  <p>And the current state is something like this:</p>
  
  <p><a href="https://i.stack.imgur.com/mragp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mragp.png" alt="State"></a></p>
  
  <ul>
  <li>And the black part of image is the device's available height.</li>
  </ul>