Provide access to configure JVM arguments

[MarkRx]

Currently the JVM arguments are deduced from a fixed set of properties in GradleExecutorGradleTestKitImpl. There does not seem to be a way to specify a JVM argument outside of that list.

For example, I am trying to setup JaCoCo instrumentation on a launched gradle script using the -javaagent JVM arguments but am unable to do so without creating a custom GradleExecutorGradleTestKitImpl.

[lacasseio]

That's a good point. I'm a bit uneasy with how the parameters are configured, but I agree we should be able to specify custom JVM arguments up to a point. One important issue is the different environments in which the test could run. We would need to check to what extent we can configure the JVM arguments of TestKit vs embedded vs Wrapper and decide if the customization should be per runner or executor.