Note that there's a bit of a privilege escalation as prefix-based
tempurls can now be used to perform listings -- but only on containers
with staticweb enabled. Since having staticweb enabled was previously
pretty useless unless the container was both public and
publicly-listable, I think it's probably fine.
This also allows tempurls to be used at the container level, but only
for staticweb responses.
Change-Id: I7949185fdd3b64b882df01d54a8bc158ce2d7032
8c4e65a6b5