gcsweb: add buckets
gcsweb: add buckets

Add world-readable buckets k8s-infra-prow-results and
k8s-infra-scalability-tests-logs

Ref: https://github.com/kubernetes/k8s.io/issues/2241
Ref: https://github.com/kubernetes/k8s.io/issues/1394

Signed-off-by: Arnaud Meukam <96190fcd0798f0afa72279990e31ddc33e4f2ea2@gmail.com>

kubernetes/k8s.io,kubernetes/k8s.io,kubernetes/k8s.io,kubernetes/k8s.io