feat: hardcode the pod prefix label

[dolfolife]

• We deleted the flag that makes the prefix label customizable and hardcode the value "cloudfoundry.org/"

#169873095

Co-authored-by: Rodolfo Sanchez rsanchez@pivotal.io

following the PR https://github.com/cloudfoundry/cf-k8s-networking/pull/17/files

[dolfolife]

how bad is it to keep it customizable?