Provide the ability to restrict non admins from adding existing custom fields to a Plan

At the moment, non Jira admins can add existing custom fields if they have write permission to the Advanced roadmap plan.

This is confusing to the Jira admins,as these custom fields may not be part of the issue screen and this data will not be shown in the Issue view until we add those fields to the screen.

Please provide the ability to restrict adding custom fields to issues inside a plan if the field is not a part of screen.