Describe the bug
Currently uploading file with content-type: multipart/form-data to an endpoint using AWS signature v4 doesn't work due to wrong signature being calculated.

To Reproduce
Steps to reproduce the behavior:

1. Create a request with AWS signature v4 auth
2. Set body to "form-data"
3. Add any file to the body
4. Click "Send"

Expected behavior
The request should succeed.

Current behavior
Request was rejected with "The request signature we calculated does not match the signature you provided."

App information (please complete the following information):

• App Type: Native App
• Postman Version: 7.20.0
• OS: Ubuntu