Add custom fields to variables list in Canned Responses

Problem Definition

When creating canned responses, there are times when information in a custom field should be provided to a customer. The current list of variables available to use in the canned responses functionality is limited to a small number of available fields (7).

Suggested Solution

Allow Agents to add custom field values by variable in the canned responses functionality.

https://support.atlassian.com/jira-service-management-cloud/docs/create-a-canned-response/#:~:text=to%20service%20requests.-,List%20of%20variables,-Here%20are%20the