Upgrade to 5.5 fails due to OOM when generating recovery file, but no entry logged in "atlassian-confluence.log"

When upgrading to version 5.5, Confluence tries to generate a recovery file first in case the upgrade fails and a rollback is required. As this is an XML backup, when the allocated memory is not large enough the following error occurs while attempting to backup the plugindata table: java.lang.OutOfMemoryError: Java heap space

When this happens, atlassian-confluence.log's last entry is:

 INFO [localhost-startStop-1] [confluence.upgrade.recovery.ConfluenceProgressMonitor] begin TABLE_DATA: [plugindata]

And the OOM error thrown in the Catalina logs is:

Caused by: java.lang.OutOfMemoryError: Java heap space

As other OOM messages (such as when performing a manual XML backup) appear in the Confluence logs, the java.lang.OutOfMemoryError: Java heap space should also be thrown in atlassian-confluence.log to avoid confusion, and potentially unnecessary roll-backs.

Workaround
Please see: Upgrade to 5.5 hangs when generating pre-upgrade recovery file