Cannot install second gitlab runner on second namespace for the same kubernetes cluster.

Summary

Using GitLab Enterprise Edition 10.8.3-ee. I have two projects, for example: proj1 and proj2. I've integrated both projects with one kubernetes cluster on GKE. Both projects have their own kubernetes namespaces, for example: "gitlab-managed-apps-proj1" and "gitlab-managed-apps-proj2" accordingly. Also proj1 is integrated with kubernetes cluster to use only gitlab-managed-apps-proj1 namespace and for proj2 kubernetes cluster is integrated to use only gitlab-managed-apps-proj2. I was able to install helm for both projects but I can install only one gitlab-runner at a time, even when I want to install second one on different namespace. proj1 helm and runner are installed on namespace gitlab-managed-apps-proj1, for proj2 when installing second runner on gitlab-managed-apps-proj2 namespace i get below error: "Something went wrong while installing GitLab Runner Kubernetes error: configmaps "values-content-configuration-runner" already exists". But values-content-configuration-runner configmap is installed only on first namespace: gitlab-managed-apps-proj1. Even more - this configmap have defined in metadata: namespace to be used only on gitlab-managed-apps-proj1 namespace. Thus I'm unable to use different namespaces on one kubernetes cluster to have two speciffic runners.

Steps to reproduce

1. Create two gitlab projects.
2. Intergate both projects with one kubernetes cluster on GKE but using two existing namespaces.
3. Install helm and gitlab runner for first project.
4. Install helm on second project.
5. Try to install runner on second project.

What is the current bug behavior?

I get error while installing second gitlab-runner on different kubernetes namespace: "Something went wrong while installing GitLab Runner Kubernetes error: configmaps "values-content-configuration-runner" already exists"

What is the expected correct behavior?

Gitlab-runner should install on second kubernetes namepsace. During installation process, existence of configmap values-content-configuration-runner should be checked only for namespace that runner will be installed on and not on whole cluster level.

Relevant logs and/or screenshots

Something went wrong while installing GitLab Runner

Kubernetes error: configmaps "values-content-configuration-runner" already exists

Output of checks

This bug happens on GitLab.com