RFR: JDK-8217473: SA: Tests using ClhsdbLauncher fail on SAP docker containers

[Jini George]

Requesting reviews for:

BugID: https://bugs.openjdk.java.net/browse/JDK-8217473
Webrev:http://cr.openjdk.java.net/~jgeorge/8217473/webrev.01/index.html
The patch includes changes to use SkippedException to skip the tests 
when canPtraceAttachLinux() in Platform.java returns false.

Thanks,
Jini.