Add explicit route weight to Vault VS

Currently the weight for the routes in the vault virtual service are implicit, which shows as a warning in kiali. Update to set explicit route weights.

e.g.

  http:
    - route:
      - destination:
          port:
            number: 8200
          host: {{ .Release.Name }}.vault.svc.cluster.local
        weight: 100

https://repo1.dso.mil/big-bang/product/packages/vault/-/blob/main/chart/templates/bigbang/istio/vault-vs.yaml?ref_type=heads