Make ARGOCD_GIT_MODULES_ENABLED configurable in argocd-cmd-params

[crenshaw-dev]

Summary

For some reason ARGOCD_GIT_MODULES_ENABLED must be set directly on the repo-server Deployment instead of being set in the argocd-cmd-params-cm ConfigMap like most env vars. It should be configurable in that ConfigMap, and the new way of configuring it should be documened.

Motivation

Not following the pattern causes confusion.

[pradeepnnv]

I would like to work on this.

[crenshaw-dev]

@pradeepnnv go for it!

[RyanTalbot]

Interested in picking this up during the week if @pradeepnnv can't get around to it.

[crenshaw-dev]

1. Add the env var to this file: https://github.com/argoproj/argo-cd/blob/master/manifests/base/repo-server/argocd-repo-server-deployment.yaml
2. Document the configmap key here: https://github.com/argoproj/argo-cd/blob/master/docs/operator-manual/argocd-cmd-params-cm.yaml

[doshianish8]

Thanks @crenshaw-dev for listing work for this ticket. I will start working on them.

[sjoukedv]

Documentation should be updated accordingly here: https://argo-cd.readthedocs.io/en/stable/user-guide/private-repositories/#git-submodules