fix: Remove centralized auth policies, change path to remaining, update docs

General MR

Summary

Cleans up the Istio Authorization Policies

Linked Issue

• 2032
• 2082

Upgrade Notices

N/A

chart/templates/bigbang/istio/authorization-policies/allow-monitoring.yaml

-{{- if and .Values.istio.enabled .Values.istio.hardened.enabled .Values.istio.hardened.monitoring.enabled -}}
-apiVersion: security.istio.io/v1
-kind: AuthorizationPolicy
-metadata:
-  name: monitoring-authz-policy
-  namespace: {{ .Release.Namespace }}
-spec:
-  action: ALLOW
-  rules:
-  - from:
-    - source:
-        namespaces: {{ .Values.istio.hardened.monitoring.namespaces | toYaml | nindent 10 }}
-        principals: {{ .Values.istio.hardened.monitoring.principals | toYaml | nindent 10 }}
-{{- end }}