fix(overlay): Overlays aren't shown on undefined origin (#3781)

modes/basic-test-mode/src/initToolGroups.ts

@@ -51,6 +51,7 @@ function initDefaultToolGroup(extensionManager, toolGroupService, commandsManage
       { toolName: toolNames.SegmentationDisplay },
     ],
     // enabled
+    enabled: [{ toolName: toolNames.ImageOverlayViewer }],
     // disabled
     disabled: [{ toolName: toolNames.ReferenceLines }],
   };