title: Open PDF from notification - nothing happens when clicking the notification
body: <p>I'm trying to open a PDF file that I downloaded from my server with my Xamarin Android App. While it's downloading, I show a progress notification in the system tray using NotificationCompat.Builder, and this works good. Then, once the download is completed, I show another notification (which replace the progress one) to say it's complete, and I'm trying to apply an intent to it, so it can launch the default PDF viewer of the device. </p>
  
  <p>I'm processing like this : </p>
  
  <pre><code>var notificationService = (NotificationManager)GetSystemService(NotificationService);
  var builder = new NotificationCompat.Builder(ApplicationContext);
  builder.SetContentTitle("Download PDF");
  builder.SetContentText("Downloading...");
  builder.SetProgress(100, 0, true);
  builder.SetSmallIcon(Resource.Mipmap.icon);
  notificationService.Notify(1337, builder.Build());
  
  Task.Run(async () =&gt;
  {
      await MyAsyncPdfDownloadMethod(filePath);
      RunOnUiThread(() =&gt; //apparently not necessary, same result with and without it
      {
          builder.SetContentText("Download completed");
          builder.SetProgress(0, 0, false);
          var notificationIntent = new Intent(Intent.ActionView, Android.Net.Uri.Parse(filePath));
          notificationIntent.SetDataAndType(Android.Net.Uri.Parse(filePath), "application/pdf");
          notificationIntent.SetFlags(ActivityFlags.ClearTop | ActivityFlags.SingleTop | ActivityFlags.NewTask);
          builder.SetContentIntent(PendingIntent.GetActivity(this, 0, notificationIntent, 0));
          builder.SetAutoCancel(true);
          notificationService.Notify(1337, builder.Build());
      });
  });
  </code></pre>
  
  <p>When the notification appears, and I click on it, it disappears, which is intended behavior thanks to SetAutoCancel. But still, it closes the system tray, and then.. Nothing. No matter that I'm still in my app or on my main screen, there is nothing.</p>
  
  <p>I went into the download folder which is where I save the file, and it's here, and I can open it correctly when clicking on it. </p>
  
  <p>I'm probably missing something, but I have no idea what it is. Any clues ?</p>