MOBILESDK-4 Use random filenames in server side. This way, test environment doesn’t get corrupted if cleaup is not successfully completed

Yeah, I already noticed that. I think that size is related to the number of bytes sent through the wire. That is: the number of bytes of the encoded JSON + the Base64 payload + content multipart headers.

What is weird is why your value is different than mine /:

Maybe we can add log in the progress callback and compare mine output with yours...