update raster layer geopackage data

Author: tschie

src/main/java/com/esri/samples/raster/raster_layer_geopackage/RasterLayerGeoPackage.png

@@ -68,6 +68,7 @@ public void start(Stage stage) throws Exception {
 
           // create a raster layer and add it to the map
           RasterLayer rasterLayer = new RasterLayer(raster);
+          rasterLayer.setOpacity(0.7f);
           map.getOperationalLayers().add(rasterLayer);
 
           // set viewpoint on the raster layer