Minor adjustment to the NBPolicy template to make ports and protocols
render as lists instead of strings.
Previously a values file like
```yaml
policies:
demo-policy:
name: "Demo Policy"
sourceGroups:
- demogroup
- demogroup2
ports:
- 443
- 80
protocols:
- tcp
- udp
```
would result in a rendered manifest like
```yaml
spec:
bidirectional: false
name: Demo Policy
ports:
- 80 443
protocols:
- tcp udp
sourceGroups:
- demogroup
- demogroup2
```
(.spec.ports[0]: expected numeric (int or float), got string)
