jenkinsfile: provide the URL to OSTree repository
Need to provide the OSTree repository URL via Jenkinsfile for ostree-based images to configure "origin" for updates from Jenkinsfile.
Fixes: APERTIS-6234
cherry-picked change from !167 (merged)
Need to provide the OSTree repository URL via Jenkinsfile for ostree-based images to configure "origin" for updates from Jenkinsfile.
Fixes: APERTIS-6234
cherry-picked change from !167 (merged)