RFR: 8072681: serviceability/dcmd/gc/RunGCTest.java looks for old output from System.gc()

[Michail Chernov]

Hi,

Can I have reviews for next small change in one test:

Issue: https://bugs.openjdk.java.net/browse/JDK-8072681
Webrev: http://cr.openjdk.java.net/~eistepan/~mchernov/8072681/webrev.00/

Test searches for "Full GC (Diagnostic Command)" string instead of "Full 
GC (System.gc())".
Added requirement for DisableExplicitGC flag. Test does not work as 
expected with DisableExplicitGC=true :  System.gc() does not trigger a 
full GC.

Thanks,
Michail