Add explicit route weight to Keycloak VS

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

e.g.

    route:
    - destination:
        host: {{ $serviceName }}
        port:
          number: {{ .Values.service.httpsPort }}
      weight: 100

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