JDK 10 RFR of JDK-8181393: Refactor shell test Selector/lots_of_updates.sh and SocketChannel/Open.sh to java

[Amy Lu]

java/nio/channels/Selector/lots_of_updates.sh
java/nio/channels/SocketChannel/Open.java which runs shell test:
      * @run shell Open.sh

Please review this patch to refactor above shell tests to java.

bug: https://bugs.openjdk.java.net/browse/JDK-8181393
webrev: http://cr.openjdk.java.net/~amlu/8181393/webrev.00/

Thanks,
Amy