Define default netpol for openstack-exporter

This change adds default network policy definitions for ingress/egress
in the prometheus-openstack-exporter chart to allow all traffic.

This also adds a netpol value override to enable network policy for
various network policy checks.

Change-Id: If1314420d5038174e8641c9809de65b23853d3f3

prometheus-openstack-exporter/values.yaml

@@ -204,6 +204,13 @@ network:
   openstack_metrics_exporter:
     port: 9103
 
+network_policy:
+  prometheus-openstack-exporter:
+    ingress:
+      - {}
+    egress:
+      - {}
+
 manifests:
   configmap_bin: true
   deployment: true

prometheus-openstack-exporter/values_overrides/netpol.yaml

@@ -0,0 +1,2 @@
+manifests:
+  network_policy: true