Add defaults for cni_plugin_dir and cni_config_dir
Add defaults for cni_plugin_dir and cni_config_dir

[#142965747]

Signed-off-by: David McClure <f2d486abbc9bad1727caf3ba835e0fcc02bb2355@pivotal.io>

cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release