Approvers should not be always treated as customers

Issue Summary

As soon as a user is added to an issue as an approver, that user is treated as a customer for the purposes of notifications, even if they're an agent. Unless they then remove themselves after approving a given issue, they'll miss out on receiving any subsequent internal notifications.

Steps to Reproduce

1. Create an issue that has an approval process.
2. Add a user that is an Agent as an approver.
3. Get the issue to the approval step.

Expected Results

The user receives the approval notifications, and also the agent notifications.

Actual Results

The user is being considered a customer and only receives customer notifications.

Workarounds

• Enable Service Desk to send both Jira and Customer notifications when the user is an agent. This can be done by going to Jira Administration > Applications, option Configuration, scroll down and change the Notification setting to "Yes, send customers both Jira Service Desk and Jira Notifications"
• Have the approvers remove themselves from the Approvers list.

Original description:

As soon as a user is added to an issue as an approver, that user is treated as a customer for the purposes of notifications, even if they're an agent. Unless they then remove themselves after approving a given issue, they'll miss out on receiving any subsequent internal notifications.

The use case here is when a customer is set as an approver and merely replies via email saying "This is approved" but doesn't visit the portal to actually click the Approve button. The agent can add herself to the Approvers field and manually approve it to transition the issue through the workflow.