Revert createDefaultCameraOrLight change for LH arc rotate

src/babylon.scene.ts

@@ -3717,7 +3717,7 @@
                 var radius = worldSize.length() * 1.5;
                 var sign = this.useRightHandedSystem ? -1 : 1;
                 if (createArcRotateCamera) {
-                    var arcRotateCamera = new ArcRotateCamera("default camera", (Math.PI / 2) * sign, Math.PI / 2, radius, worldCenter, this);
+                    var arcRotateCamera = new ArcRotateCamera("default camera", -Math.PI / 2, Math.PI / 2, radius, worldCenter, this);
                     arcRotateCamera.lowerRadiusLimit = radius * 0.01;
                     arcRotateCamera.wheelPrecision = 100 / radius;
                     camera = arcRotateCamera;