We downloaded the example Java vision project from the Raspberry image install and put it into a VSCode project.
The relevant jars (cameraserver, cscore etc) were put into a subfolder \usr\local\frc\java because that made Gradle happy, and the project builds.
The issue we have is that the Intellisense in VSCode is not picking up some of the jars - get the red squiggly lines for
import edu.wpi.cscore.VideoSource;
import edu.wpi.first.cameraserver.CameraServer;
and others.
Put the jars into the top directory of the project instead; Intellisense seems to be able to pick them up from there. That’s also where they’re put in the examples of the 2019.2.1 release of FRCVision.