Hello Kuldeep,
We're beginning a new project focused on a new gateway management user experience. There are many things we want to accomplish with this project, and it's likely that it will lead to many releases over a long period of time. However, maker/checker functionality to help many the change lifecycle of gateway configuration, including but not limited to service definitions and policies, will be a part of that project.
In the meantime, as Joseph pointed out, customers use various existing capabilities together with their own tools and processes to accomplish something similar today. Managing gateway configuration as code in the form of Restman, or more recently Graphman, bundles exported to git or other source repositories is often a part of that. That can be done across gateway form factors, and without the Layer7 Operator for container gateway. However, the Layer7 Operator is uniquely capable for doing that dynamically for container gateways, and otherwise provides the automation for doing it that customers would have to come up with on their own using Restman or Graphman.