Returns the maximum number of invalid login records that the server keeps in memory.
If the number of invalid login records is equal to or greater than this value,
the server's garbage collection purges the records that have expired.
A record expires when the user associated with the record has been locked out.
<p>
The lower the threshold, the more often the server uses its resources to collect garbage.
(Interface=weblogic.management.security.authentication.UserLockoutManagerMBean Attribute=getLockoutGCThreshold)