[Operational Policies][UX] API Creators can drag and drop polices for Published APIs

[tgtshanika]

Description:

API Creators can drag and drop/modify individual policies for APIs which are in the Published state. Ideally drag and drop functionality should be disabled too, as the creators are not allowed to attach new mediation policies when the API is already published.

Steps to reproduce

1. Login as a creator user
2. Create an API and navigate to the Policies tab
3. You can drag and drop policies. But can't save the mediation flow, as it's restricted for API creators.

[tgtshanika]

This is the default behavior of already published APIs