// The default policy is decided by the existing finalizer set in the
  // metadata.finalizers and the resource-specific default policy.
  // Acceptable values are: 'Orphan' - orphan the dependents; 'Background' -
  // allow the garbage collector to delete the dependents in the background;
  // 'Foreground' - a cascading policy that deletes all dependents in the
  // foreground.
  // +optional