Enable git lfs from ods-start

[gerardcl]

We have detected that git LFS is not supported in ods-pipeline. Since it is a feature of current ODS we could try to add it here too.

Proposal would be to just replicate the installation from the jenkins-agent-base image to the ods-start image.

[gerardcl]

We have tested adding git LFS in a custom task with success.
The addition of this feature would be pretty simple like in ods-start just have a script check like (and of course first having git lfs installed in the ods-start image):

  # then check if there are lfs tracked files
  if [ `git lfs ls-files --all | wc -l` -gt 0 ]; then
    # if yes init and pull lfs
    echo "Git LFS detected, pulling files..."
    git lfs install # this enables the missing hooks to later be able to git lfs pull
    git lfs pull
  fi

And that to be added here:

ods-pipeline/deploy/central/tasks-chart/templates/task-ods-start.yaml

Line 171 in 89b6b55

FYI @michaelsauter @ManuelFeller

[gerardcl]

I was now thinking that we might want to be added in the ods-start package so we can also provide tests, but, do we need to test this?

[michaelsauter]

In general, everything should be in the ods-start package, see https://github.com/opendevstack/ods-pipeline/blob/master/docs/adr/20210511-executing-step-scripts.md.