fix geocode typo

Author: jjspace

Apps/Sandcastle/gallery/Clipping Regions.html

@@ -43,7 +43,7 @@
           animation: false,
           sceneModePicker: false,
           baseLayerPicker: false,
-          geocoder: Cesium.IonGeocoderProviderType.GOOGLE,
+          geocoder: Cesium.IonGeocodeProviderType.GOOGLE,
         });
         const scene = viewer.scene;