Ability to customize the secret token used to authenticate the backend API when importing openapi spec

The customer is asking to add the functionality to customize/update the secret token used to authenticate the backend API when importing openapi spec.

New optional parameter will be added to openapi import command

Something like

--backend-api-secret-token=<value>        Customize backend api secret token

In addition, we could also implement another optional parameter for the custom Host request header for backend api requests. This is needed if your API backend only accepts traffic from a specific host.

--backend-api-host-header=<value>        Customize backend api host request header