Move enforcement action for `disallow-nodeport-services` to BB override

Follow on to https://repo1.dso.mil/groups/platform-one/big-bang/-/epics/135

Instead of having the package default be in enforcing mode, we should have the package default as "audit" but have BB override this to be enforcing.

This is no real change in behavior, assuming people install from BB, but provides a better way of managing the policies from Big Bang rather than messing with the package default.