Registry internal key populate should be in Rails recipe
Part of https://gitlab.com/gitlab-com/infrastructure/issues/2149
When Registry is disabled on a node AND we want to use a custom certificate for the Rails <-> Registry communication, the key cannot be created by the package. This is because we won't be running the registry recipe which would normally create this file.
We should move this part to gitlab-rails recipe and create it if node['registry']['internal_key'] is set and node['gitlab']['gitlab-rails'['registry_enabled']=true
.
/cc @omame @balasankarc