title: DividerItemDecoration will not work no matter what I do
body: <p>This is the code for setting the decoration :-</p>
  
  <pre><code>recyclerView.addItemDecoration(new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.HORIZONTAL));
  </code></pre>
  
  <p>This is the xml :-</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle"&gt;
      &lt;size android:height="1dp" /&gt;
      &lt;solid android:color="@android:color/black" /&gt;
  &lt;/shape&gt;
  </code></pre>
  
  <p>I have tried setting the drawable using <code>DividerItemDecoration.setDrawable(Drawable drawable)</code>
  and setting the <code>android:listDivider</code> item in my theme to point to the xml.</p>
  
  <p>I have also tried setting the width to 1dp. Absolutely nothing works.</p>
  
  <p>Any help is appreciated, thanks.</p>