RFR(S): 8209164: [TESTBUG] Apply jtreg skipped status to cds tests

[Mikhailo Seledtsov]

Please review this straight forward change. Now that JTReg harness 
supports the "skipped status",
this change updates CDS and AppCDS tests to use this mechanism where 
applicable.

     JBS: https://bugs.openjdk.java.net/browse/JDK-8209164
     Webrev: http://cr.openjdk.java.net/~mseledtsov/8209164.01/index.html
     Testing:
         1. Locally: exercised tests under runtime/SharedArchiveFile and 
runtime/appcds on Linux-x64
            No new failures
     2. Run runtime/SharedArchiveFile and runtime/appcds via distributed 
test system
            Run tier1,tier2
            In progress

Thank you,
Misha