fix(helm): Allow metrics networkpolicy only from namespace (#17555)

Signed-off-by: Jan-Philipp Litza <jplitza@users.noreply.github.com>
Co-authored-by: J Stickler <julie.stickler@grafana.com>

Author: jplitza

production/helm/loki/templates/networkpolicy.yaml

@@ -96,7 +96,7 @@ spec:
     - ports:
         - port: http-metrics
           protocol: TCP
-    {{- if .Values.networkPolicy.metrics.cidrs }}
+    {{- if or .Values.networkPolicy.metrics.cidrs .Values.networkPolicy.metrics.namespaceSelector }}
       from:
       {{- range $cidr := .Values.networkPolicy.metrics.cidrs }}
         - ipBlock: