Add content provider job, which builds containers using `current` dlrn
tag on same release branch as regular content-provider job.
Apart from new content provider job, the change adds new variable called
`minor_update`, which enables to consume containers created by new
content provider job in depended multinode-oooq-container-updates job.
minor_update variable is used in featureset068.
The featureset is activated in jobs for wallaby branch and onwards.
Train job uses featureset038 as previously.
Related-Bug: #2015993
Change-Id: I7a7713be0cd15321d5b16f6b8ca85f06d296219f
9e7cf30337