JCLOUDS-458:Multipart Related Upload

"If you have metadata that you want to send along with the data to upload, you can make a single multipart/related request. As with simple, media-only requests, this is a good choice if the data you are sending is small enough to upload again in its entirety if the connection fails."
Use `replaceHeader` and `HttpHeaders` instead:

```
request.toBuilder().replaceHeader(HttpHeaders.CONTENT_TYPE, "Multipart/related; boundary= " + BOUNDARY_HEADER).build();
```