Figure out a way to create Index State Management policies using terraform for user ES module

[vijay-veeranki]

Background

To save costs but store more data, we used a policy similar to https://github.com/ministryofjustice/cloud-platform-terraform-elasticsearch/blob/cold/ism-policy.tpl.json The policy is now applied through terraform for live ES.

Try the same approach for user ES, and let the concourse apply it, or if we feel like giving more permissions to the concourse user, create a guide for users to add this policy in kibana manually.

Approach

Using this PR test for the user ES module. https://github.com/ministryofjustice/cloud-platform-infrastructure/pull/1865/files

Definition of done

• [ ] terraform code in ES module updated/guidence added for user to add the policy
• [ ] another team member has reviewed