centos symmetry with ubuntu: centos_net_manager_test.go: Moved some test code to increase symmetry with ubuntu_net_manager_test.go.
centos symmetry with ubuntu: centos_net_manager_test.go: Moved some test code to increase symmetry with ubuntu_net_manager_test.go.

This commit increases the symmetry between centos and ubuntu test code, making it easier to compare the actual functional differences between the two sets of code.

cloudfoundry/bosh-agent,cloudfoundry/bosh-agent