Both tests in test/jdk/jdk/jfr/api/consumer/streaming/TestChunkGap.java and test/jdk/jdk/jfr/api/consumer/streaming/TestFilledChunks.java, uses almost 500m with G1 and the default heap size is 512m.

When these tests are run with ZGC, we either get OOMEs or timeouts when the attach listener thread repeatedly catch the OOMEs.

I propose that we explicitly set the heap size to something higher, say 768m.