CR# 6293673: Need to retain the original session information when sending out session timeout notification

The new com.sun.identity.session.property.doNotTrimList property in the AMConfig.properties file can contain list of comma separated session property names. Once a session is timed out, the properties defined in this list will not be trimmed off, so that they can be accessed before the session is purged. For example:

com.sun.identity.session.property.doNotTrimList=UserId,HostName