AETHER-487 Add support of k8s 1.18

Change-Id: I759b71546e6ba2fc1a52ab135ea26c403fecc417
diff --git a/omec/omec-control-plane/templates/_helpers.tpl b/omec/omec-control-plane/templates/_helpers.tpl
index 0833603..7982cf6 100644
--- a/omec/omec-control-plane/templates/_helpers.tpl
+++ b/omec/omec-control-plane/templates/_helpers.tpl
@@ -61,7 +61,11 @@
   labels:
 {{ tuple $saName $context | include "omec-control-plane.metadata_labels" | indent 4 }}
 ---
+{{- if semverCompare ">=1.16-0" $context.Capabilities.KubeVersion.GitVersion }}
+apiVersion: rbac.authorization.k8s.io/v1
+{{- else }}
 apiVersion: rbac.authorization.k8s.io/v1beta1
+{{- end }}
 kind: RoleBinding
 metadata:
   name: {{ $saName }}
@@ -77,7 +81,11 @@
     name: {{ $saName }}
     namespace: {{ $saNamespace }}
 ---
+{{- if semverCompare ">=1.16-0" $context.Capabilities.KubeVersion.GitVersion }}
+apiVersion: rbac.authorization.k8s.io/v1
+{{- else }}
 apiVersion: rbac.authorization.k8s.io/v1beta1
+{{- end }}
 kind: Role
 metadata:
   name: {{ $saName }}