In order to comply with the OCI specification, the agent should write the OCI specification to a 'config.json' file within the guest container's bundle path.

This issue was discovered when trying to use an existing OCI hook within the guest. This hook reads the bundle path from the HookState passed over stdin, then attempts to open /path/to/bundle/config.json which doesn't exist because the bundle path is wrong and because config.json is never written. The reason the cwd needs to be changed is that CreateLibcontainerConfig sets the bundle path to cwd: