Add a BUILD_ORIGIN field - T10021
This MR makes use of a couple of metadata variables, useful to determine the origin. The metadata is written to the same build location as inherited by the children jobs (image recipes, docker image, tiny image etc).
Ultimately, it'll help is determining a built artifact's origin; whether it was started from builds-orchestrator or else where.
Signed-off-by: Ritesh Raj Sarraf ritesh.sarraf@collabora.com