Webhook RBAC template bug

[r00tvvm]

Looks like these are bugs in RBAC template.

1. ServiceAccount name and namespace are same values
   https://github.com/instana/instana-autotrace-webhook/blob/main/incubator/instana-autotrace-webhook/templates/mutating-webhook-rbac.yaml#L6-L7
   Fix: name: {{ .Release.Name }}

2. Static defining of app.kubernetes.io/instance
   https://github.com/instana/instana-autotrace-webhook/blob/main/incubator/instana-autotrace-webhook/templates/deployment.yml#L18
   is causing conflict in case webhook deployed under other release name
   https://github.com/instana/instana-autotrace-webhook/blob/main/incubator/instana-autotrace-webhook/templates/_helpers.tpl#L43
   Fix:

L18:
   selector:
    matchLabels:
      app.kubernetes.io/name: {{ include "instana-autotrace-webhook.name" . }}