test: Fix rhsmd cleanup in check-packagekit
test: Fix rhsmd cleanup in check-packagekit

When disabling /usr/libexec/rhsmd (on RHEL images), re-enable it at the
end of the test. This unbreaks running more than one check-packagekit
test on an external testbed.

Closes #12717
deryni/cockpit,moraleslazaro/cockpit,deryni/cockpit,cockpituous/cockpit,garrett/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,cockpituous/cockpit,deryni/cockpit,moraleslazaro/cockpit,cockpit-project/cockpit,martinpitt/cockpit,deryni/cockpit,garrett/cockpit,mvollmer/cockpit,martinpitt/cockpit,martinpitt/cockpit,deryni/cockpit,martinpitt/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,cockpit-project/cockpit,garrett/cockpit,moraleslazaro/cockpit,garrett/cockpit,cockpituous/cockpit,mvollmer/cockpit,garrett/cockpit,cockpituous/cockpit,mvollmer/cockpit,deryni/cockpit,deryni/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,cockpit-project/cockpit,mvollmer/cockpit