RFR 8144806: sun/security/tools/keytool/standard.sh fails intermittently at deleting x.jks

[bhanu . prakash . gopularam]

Hi All,

Please review fix for following issue:
JBS bug: https://bugs.openjdk.java.net/browse/JDK-8144806

Webrev: http://cr.openjdk.java.net/~bgopularam/bhanu/8144806/webrev.00/

The patch fixes intermittent test failure. The fix uses 
deleteFileIfExistsWithRetry(..) from test library class FileUtils.

I have validated the fix with repeated-run on all supported platform.

Thanks,
Bhanu