Improved admissions controll

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This is not a problem but an improvement for LEAST PRIVILAGED access. We believe that providing too much access for admissionregistration.k8s.io to ALL resources is bad practice.

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Restrict rules access for the injector-clusterrole in the following template file: charts/vault/templates/injector-clusterrole.yaml:

Original/current code:

rules:

- apiGroups: ["[admissionregistration.k8s.io](http://admissionregistration.k8s.io/)"]

resources: ["mutatingwebhookconfigurations"]

verbs:

- "get"

- "list"

- "watch"

- "patch"

NEW proposed code: (remove patch from all resources and specify it to only to the vault-agent-injector-cfg resource):

- apiGroups: ["[admissionregistration.k8s.io](http://admissionregistration.k8s.io/)"]

resources: ["mutatingwebhookconfigurations"]

verbs:

- "get"

- "list"

- "watch"

- apiGroups: ["[admissionregistration.k8s.io](http://admissionregistration.k8s.io/)"]

resources: ["mutatingwebhookconfigurations"]

resourceNames:

- vault-agent-injector-cfg

verbs:

- "patch"

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**Additional context**
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Start with charts/vault/templates/injector-clusterrole.yaml and inspect the injector-clusterrole rules for admissionregistration.k8s.io. Restrict patch access to the vault-agent-injector-cfg resource while retaining the listed read verbs for mutatingwebhookconfigurations; done means the rendered rule matches the proposed access scope.

Written by the indexing model from the issue text.