JDK 10 RFR of JDK-8181575: Refactor locale related shell test java/nio/charset/spi/basic.sh to java

[Amy Lu]

java/nio/charset/spi/basic.sh

Please review this patch to refactor the shell test to java.

bug: https://bugs.openjdk.java.net/browse/JDK-8181575
webrev: http://cr.openjdk.java.net/~amlu/8181575/webrev.00/

Thanks,
Amy