Istio sidecar NetworkPolicy Addition

Loki is istio injected, but had no istio or istio.enabled value or Istio related NetworkPolicy was included.

README.md

@@ -86,6 +86,7 @@ helm install loki chart/
 | networkPolicies.enabled | bool | `false` |  |
 | networkPolicies.controlPlaneCidr | string | `"0.0.0.0/0"` |  |
 | monitoring.enabled | bool | `false` |  |
+| istio.enabled | bool | `false` |  |
 | client | object | `{}` |  |
 | nodeSelector | object | `{}` |  |
 | persistence.enabled | bool | `false` |  |