selinux: Comment out file context for cockpit-agent

selinux-policy-targetted puts the cockpit-agent file context in the
wrong selinux module, so we cannot replace it. For now just rely on
that definition to be correct and comment this out here.

https://bugzilla.redhat.com/show_bug.cgi?id=1139138

Reviewed-by: Marius Vollmer <marius.vollmer@redhat.com>
selinux: Our own version number for cockpit selinux policy

This lets us easily see whether it's installed or not. Like
this:

$ sudo semodule -l | grep cockpit

Closes #1136
Reviewed-by: Marius Vollmer <marius.vollmer@redhat.com>