title: Failed to highlight a selected item on RecyclerView
body: <p>I've a master-details app that has split view screen using Fragments. The master screen is a list containing RecyclerView. Here's the layout XML.</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical"&gt;
  
        &lt;TextView
              android:layout_width="match_content"
              android:layout_height="wrap_content"
              android:padding="5dp"
              android:text="Page Title" /&gt;
  
        &lt;android.support.v7.widget.RecyclerView
               android:id="@+id/page_list"
               android:layout_width="match_parent"
               android:layout_height="match_parent" /&gt;                
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>And the item row layout xml is as follows.</p>
  
  <pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt;
   &lt;LinearLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="horizontal"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:paddingTop="10dp"
      android:paddingBottom="10dp"
      android:background="?android:attr/selectableItemBackground"
      android:clickable="true"
      android:id="@+id/item_layout"&gt;
  
  &lt;TextView
      android:id="@+id/contact_name"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="1"
      /&gt;
  
  &lt;Button
      android:id="@+id/message_button"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:paddingLeft="16dp"
      android:paddingRight="16dp"
      android:textSize="10sp"
      /&gt;
  &lt;/LinearLayout&gt; 
  </code></pre>
  
  <p>On the adapter class, I created a variable to hold position of selected item</p>
  
  <pre><code>public class ListAdapter extends RecyclerView.Adapter&lt;ListAdapter.ListViewHolder&gt; {
       private int selectedPos;
  
       @Override
       public void onBindViewHolder(ListViewHolder holder, int position) {
         holder.itemView.setSelected(selectedPos == position);
         holder.bind(mData.get(position));
       }
  
       class ListViewHolder extends RecyclerView.ViewHolder {
           public ListViewHolder(View itemView) {
               super(itemView);
           }
           public void bind(ListEntity entity) {
             //UI rendering
           }
           @OnClick(R.id.layout_campaign)
           public void onItemClicked(View view) {
              notifyItemChanged(selectedPos);
              selectedPos = getLayoutPosition();
              notifyItemChanged(selectedPos);
           }
  }
  </code></pre>
  
  <p>When I click an item on the list, the list item is not highlighted. Looked into quite a few similar posts regarding this issue, but couldn't get it to work. Am I missing anything?</p>