[stable/nats] Update sts apiVersion to 'apps/v1' - Mandatory for K8s 1.16 (#17282)

Signed-off-by: juan131 <juan@bitnami.com>

stable/nats/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 name: nats
-version: 4.1.3
+version: 4.1.4
 appVersion: 2.0.4
 description: An open-source, cloud-native messaging system
 keywords:

stable/nats/templates/statefulset.yaml

@@ -1,5 +1,5 @@
 {{- if or (eq .Values.resourceType "statefulset") (not (contains .Values.resourceType "deployment")) }}
-apiVersion: apps/v1beta2
+apiVersion: apps/v1
 kind: StatefulSet
 metadata:
   name: {{ template "nats.fullname" . }}