Fixes #6808/BZ1124058: fixing permissions of product buttons.

Several product buttons were using the incorrect permission
in determining whether to disable the buttons.  This commit
fixes these incorrect permissions.

http://projects.theforeman.org/issues/6808
https://bugzilla.redhat.com/show_bug.cgi?id=1124058
I think this is a misnomer and not a concept used anywhere else in light of our recent changes - file an issue to address this for api/ui/hammer?