JCMA disables dependent plugins during update, which can resort in a partial outage

Issue Summary

When upgrading JCMA, plugins that dynamically import functionality from the migrations plugin need to be restarted. This is to support integration with the migrations plugin.

This is a problem because as more plugins adopt JCMA integrations, they will be restarted. Some of these plugins may depend on core system plugins, like Jira Software. This will result in them getting restarted

The user experience is that a seemingly benign app update causes a cluster outage while major plugins are restarted. This risk of this is not documented anywhere or highlighted to the user during the update operation.

Steps to Reproduce

1. Install some plugins that import JCMA functionality (EG JSU, Zephyr, Structure, ScriptRunner....)
2. Update JCMA, EG from 1.4.4 to 1.6.5

Actual Results

Dependent plugins are restarted, EG:

2022-02-14 13:30:38,552+1100 UpmAsynchronousTaskManager:thread-1 INFO admin 733x237x5 1r4psju 127.0.0.1 /rest/plugins/1.0/installed-marketplace [c.a.plugin.manager.DefaultPluginManager] To disable plugins '[com.atlassian.jira.migration.jira-migration-plugin]', we need to first disable all dependent enabled plugins: [com.onresolve.jira.groovy.groovyrunner(DYNAMIC), com.almworks.jira.structure(DYNAMIC), com.thed.zephyr.je(OPTIONAL), com.googlecode.jira-suite-utilities(DYNAMIC)]...

Ideas for solutions

• Re-work how dependent plugins utilise JCMA functionality
• Somehow prevent dependent plugin restart upon JCMA upgrade
• Document this behaviour in a way that is easily consumable by the Jira admin.