RFR of JDK-8166763: java/rmi/* tests fail intermittently with "Port already in use" in RMID.start()

[Hamlin Li]

Would you please review the below patch?

bug: https://bugs.openjdk.java.net/browse/JDK-8166763
webrev: http://cr.openjdk.java.net/~mli/8166763/webrev.00/

Not all modified tests failed, the patch is to improve the test quality.

Thank you
-Hamlin