Ensure Vulnerabilities Index creation and backfill during ES bootstrap

Check and include ES vulnerability index related migrations:

1. When an admin enables Vulnerabilities Index from the Search admin settings page.
2. When a Gitlab Developer sets up ES using GDK.

We have to ensure that the Vulnerabilities index with the revised mappings are created and the backfill to ES index is completed.

Especially when ES is being setup by a GitLab developer for development and when a dedicated instance admin is setting up ES.

For more context: See slack thread