Unnecessary Vector usage in DocPrintJob implementations

There are 3 implementations of javax.print.DocPrintJob in the JDK:

1. PSStreamPrintJob
2. UnixPrintJob
3. Win32PrintJob

They have Vector fields 'jobListeners', 'attrListeners', 'listenedAttributeSets', but they are always accessed only under synchronized(this) blocks. It means we can safely replace them with ArrayList.