title: Issue downloading images using image_downloader package
body: <p>So, I have been successful in downloading an image from a firebase URL and storing it in the device, The issue that I am facing is that it also downloads a file with the same name as the downloaded image, but without file type.</p>
  <p>Example, downloading Image.jpg will also download a file named Image, and it is visible within the device.</p>
  <pre><code>saveImage(Message message) async {
  String url = message.photoURL;
  try {
    var imageId = await ImageDownloader.downloadImage(
      url,
      destination: AndroidDestinationType.custom(directory: 'exampleDir'),
    );
    if (imageId == null) {
      return;
    }
    setState(() {
      SnackBar snackBar = SnackBar(
        content: Text('Image Saved!'),
      );
      _scaffoldKey.currentState.showSnackBar(snackBar);
      Timer(Duration(seconds: 2), () {});
    });
    if (imageId == null) {
      return;
    }
  } on PlatformException catch (error) {
    print(error);
  }
  </code></pre>
  <p>}</p>
  <p><a href="https://i.stack.imgur.com/pwO6f.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pwO6f.png" alt="Issue with downloading using Image_Downloader package" /></a></p>
  <p>Any suggestions?</p>
  <p>Thanks</p>