networkPolicies vs networkPolicy - bug for a long time

I noticed this with argocd a long while ago. Should probably make them just be one as ".Values.networkPolicy.enabled" isn't documented in values.

https://repo1.dso.mil/big-bang/product/maintained/redis/-/blob/main/chart/values.yaml?ref_type=heads#L57

https://repo1.dso.mil/big-bang/product/maintained/redis/-/blob/main/chart/templates/networkpolicy.yaml?ref_type=heads#L6