title: DownloadManager set title change my filename
body: <p>I used DownloadManager in my application to download file from internet. 
  Here's my code.</p>
  
  <pre><code>DownloadManager downloadManager = (DownloadManager) ui.activity.getSystemService(Activity.DOWNLOAD_SERVICE);
  Uri Download_Uri = Uri.parse("http://dl.appvn.com/appvn.apk");
  DownloadManager.Request request = new DownloadManager.Request(Download_Uri);
  
  
  request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE);
                    .
  request.setAllowedOverRoaming(false);
  request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,"appvn.apk");
  
  request.setTitle("AppStoreVN");
  
  request.setDescription("Android Data download using DownloadManager.");
  
  downloadManager.enqueue(request);
  </code></pre>
  
  <p>I used setTitle &amp; setDescription to change the info show on Notification bar. But it also change my file name like title ("AppStoreVN" while it should be "appvn.apk").
  Anyone have ideas? Thanks</p>