[9] 8173956: KeyStore regression due to default keystore being changed to PKCS12

[Vincent Ryan]

Please review this fix to correct support for mixed-case aliases in PKCS12 
keystores.
Thanks.

Webrev: http://cr.openjdk.java.net/~vinnie/8173956/webrev.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8173956