title: Unable to add margin between items in horizontal RecycleView
body: <p>I use horizontal <code>RecyclerView</code>, the margin between my list item is constant, I want to increase the list item gap, I tried increasing the <code>layout_margin</code> but there is no change.</p>
  
  <p>Below is my list item layout</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v7.widget.CardView 
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_margin="30dp"
  android:background="@color/colorWhite"
  app:cardElevation="2dp"
  app:cardCornerRadius="5dp"
  app:cardPreventCornerOverlap="false"
  app:cardUseCompatPadding="true"&gt;
  
  &lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:background="?android:selectableItemBackground"
      android:orientation="vertical"
      android:padding="0dp"&gt;
  
      &lt;ImageView
          android:id="@+id/itemImage"
          android:layout_width="170dp"
          android:layout_height="170dp"
          android:layout_gravity="center_horizontal"
          android:layout_margin="10dp"
          android:scaleType="fitCenter"
          android:src="@drawable/ic_launcher_background" /&gt;
  
  
      &lt;TextView
          android:id="@+id/tvTitle"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_below="@id/itemImage"
          android:gravity="center"
          android:padding="5dp"
          android:text="Sample title"
          android:textColor="@color/colorTextBlack"
          android:textSize="16dp" /&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="center"
          android:layout_marginBottom="14dp"
          android:gravity="center"
          android:textSize="12dp"
          android:textColor="#9f9f9f"
          android:text="2 Aug, London" /&gt;
  
  &lt;/LinearLayout&gt;
  
  &lt;/android.support.v7.widget.CardView&gt;
  </code></pre>
  
  <p>This is the view I am getting, I want to increase the gap between the items
  <a href="https://i.stack.imgur.com/gwtU4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gwtU4.png" alt="enter image description here"></a></p>
  
  <p>can someone help me with the issue? </p>