fix: helm values env-vars to be compatible with keycloak 23.0.7

See #234 (closed)

This change fixes the following 2 variables to be consistent with the given Keycloak chart (23.0.7):

  extraEnvVars:
    - name: KEYCLOAK_EXTRA_ARGS
      #value: "-Dkeycloak.import=/config/gaia-x-realm.json" (previously)
      value: "--import-realm"
...
  extraVolumeMounts:
    - name: config
      #mountPath: "/config" (previously)
      mountPath: "/opt/bitnami/keycloak/data/import"
      readOnly: true