#8947 implemented support for the If-Match and If-None-Match headers for S3 PUT
Object requests; however, this support did not extend to multi-part copy and
upload requests. These headers are implemented via inclusion in the
CompleteMultipartUpload request.
This updates the auto generated code also which was needed for multipart copy.
The If-Match and If-None-Match headers were being dropped rather
than implemented in the Put Object request to S3. These headers
make requests conditional which allow AWS S3 Bucket Policies to
prevent Object overwriting.
Sean Turner