RFR: ZGC: Fix JFR *.jfc files

[Erik Gahlin]

Looks good. That's a great test.

Erik

> Hi all,
>
> The JFR *.jfc files have incorrect attributes for the ZGC events. This 
> causes the 
> test/jdk/jdk/jfr/event/metadata/TestDefaultConfigurations.java test to 
> fail.
>
> http://cr.openjdk.java.net/~stefank/zgc/fixJFRFiles/
>
> Thanks,
> StefanK