Make it possible to inspect an initial response and pass it to ResumableRequestReader. This makes it possible to inspect an initial response and passing it to ResumableRequestReader to avoid making an extra request. Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack) Upstream-commit: f033ce3ee9ee055612acacde537687e41865e14f Component: engine