Audit log migration: The JSW 8.8 and JSD 4.8 upgrade nodes documentation is providing conflicting/wrong info.

Issue Summary

After upgrading Jira software server and Jira service desk server (not data center), upon restart, the Audit log migration is taking place and is taking a long time to finish. Adding the "jira.advanced.audit.log.migration.limit=10" parameter had no effect.  Based on the Upgrade notes, this supposed to take place in the backgroud, but that is not the case. 
 
In the jira-software-8-8-x-upgrade-notes and jira-service-desk-4-8-x-upgrade-notes at the top part of the document, it notes: "The migration runs in the background for all Server and Data Center upgrade paths (ZDU included) and does not stop Jira being operational." 

But then at the bottom of the jira-software-8-8-x-upgrade-notes, under the below section, there is the conflicting note where only in case of ZDU (Datacenter Zero Downtime Upgrade) this process runs in the background. This appears to be the correct statement based on what customers are experiencing. 

  Upgrade procedure

  
As the result of introducing the Advanced auditing feature, we'll be migrating your old audit log (up to 10 million records) on upgrade. Depending on the platform you're using and the size of your audit log, the migration might take up to several hours.

If you migrate with ZDU, your migration task will run in the background, and Jira will still be accessible to users.

You can use the{{ }}jira.advanced.audit.log.migration.limit flag in the Jira properties file to limit the number of events you want to migrate or to turn off the migration altogether. In that case, you will only see the new events in your upgraded Audit log view, and the past events will remain invisible until you have performed the migration.

Steps to Reproduce

Migrate to JSW 8.8/ JSD4.8

Expected Results

The Audit Log Migration should run in the background upon restarting Jira after the upgrade.

Actual Results

Audit log migration is happening while starting Jira after the upgrade and it takes a while to complete. 

Workaround

No known workaround