Helm chart uses metrics in values.yaml and Metrics in the deployment.yaml template. This leads to an error if the Helm chart user doesn't specify Metrics.
Helm install failed for release cert-manager/cert-manager-sync with chart cert-manager-sync@0.1.0: template: cert-manager-sync/templates/deployment.yaml:18:22: executing "cert-manager-sync/templates/deployment.yaml" at <.Values.Metrics.enabled>: nil pointer evaluating interface {}.Metrics