RFR: 8242031: TestLookForUntestedEvents.java fails because newly added test tests experimental events

[Stefan Karlsson]

Hi all,

Please review this small, trivial patch to (again) fix 
TestLookForUntestedEvents.

https://cr.openjdk.java.net/~stefank/8242031_/webrev.01
https://bugs.openjdk.java.net/browse/JDK-8242031

A recent change added tests for experimental JFR events, but didn't add 
the events to the list of experimental events in TestLookForUntestedEvents.

Thanks,
StefanK