[Misc] Define the "screenshotDirectory" system property for Surefire/Failsafe...

[Misc] Define the "screenshotDirectory" system property for Surefire/Failsafe plugins only when not executing docker-based tests since it's not used for them (the screenshot directory is computed based on the "maven.build.dir" system property for them). Incidentally this is also trying to fix a problem with Gradle Enterprise not caching the Surefire/Failsafe execution.