title: Uploaded file to S3 via PreSigned URL from Flutter App. but the file is corrupted when i download it
body: <p>I am working on a Flutter App, where I upload image file (PUT Request) to AWS S3 using a presigned URL. The upload is successful as I can see the file in S3. But when I click and download it from the bucket, the downloaded file is corrupted.</p>
  
  <p>I am using Dio library for uploading the file.
  Uploading the image file as binary via postman works perfectly</p>
  
  <pre><code>uploadFileToPresignedS3(
      File payload, String fileName, String presignedURL) async {
    try {
      Dio dio = new Dio();
  
      FormData formData = new FormData.from(
          {"name": fileName, "file1": new UploadFileInfo(payload, fileName)});
      dio.put(presignedURL, data: formData);
    } catch (ex) {
      print(ex);
    }
  }
  
  
  </code></pre>
  
  <p>Expected: The uploaded file not to be corrupted</p>
  
  <p>Actual result: The uploaded file is corrupted</p>