Add istio-cni config map to reliability overlays
What
The change adds a new ConfigMap named 'reliability-overlay-istio-cni-values-${cluster}' to the 'istio-system' namespace. This ConfigMap contains values for the Istio CNI plugin, which is used to provide network connectivity for Istio services. The change also adds the 'istio-cni.yaml' file to the 'kustomization.yaml' files for the for pre-gitlab-gke
and gstg-giltab-gke
clusters.
Why
All istio base configs should live within the same tenant, for a simpler setup.
Related Issue: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/24157
Edited by Marcel Chacon