title: How to send(POST) xml file using volley in android
body: <p>Is there a way to send an xml file using POST query in Volley? The
  file contains products like:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8" ?&gt;
  &lt;products_list&gt;
      &lt;product&gt;
          &lt;tag1&gt;&lt;/tag1&gt;
          &lt;tag2&gt;&lt;/tag2&gt;
          &lt;tag3&gt;&lt;/tag3&gt;
      &lt;/product&gt;
      &lt;product&gt;
          &lt;tag1&gt;&lt;/tag1&gt;
          &lt;tag2&gt;&lt;/tag2&gt;
          &lt;tag3&gt;&lt;/tag3&gt;
      &lt;/product&gt;
      ...
  &lt;/products_list&gt;
  </code></pre>
  
  <p>I know that Volley has StringRequest but how do I transfer a file like I listed above to server?</p>