fix ServiceAccount creation in helm chart (#13197)

Fixed the variable name on the templated and added name.

helm/minio/templates/serviceaccount.yaml

@@ -2,6 +2,6 @@
 apiVersion: v1
 kind: ServiceAccount
 metadata:
-  name: {{ include "minio.serviceAccountName" . | quote }}
+  name: {{ .Values.serviceAccount.name | quote }}
   namespace: {{ .Release.Namespace | quote }}
 {{- end -}}

helm/minio/values.yaml

@@ -324,8 +324,8 @@ podDisruptionBudget:
 serviceAccount:
   create: true
   ## The name of the service account to use. If 'create' is 'true', a service account with that name
-  ## will be created. Otherwise, a name will be auto-generated.
-  name:
+  ## will be created.
+  name: "minio-sa"
 
 metrics:
   serviceMonitor: