RFR 8048619: Implement tests for converting PKCS12 keystores

[zaiyao liu]

Hi Max,

Please review the code change,the purpose of this fix is implement tests 
that convert PKCS12 keystores to other formats.

Webrev: http://cr.openjdk.java.net/~tyan/kevin/JDK-8048619/webrev01/
Bug:    https://bugs.openjdk.java.net/browse/JDK-8048619

Thanks

Kevin