update symbol reference (#737)

Author: jenmerritt

symbology/picture-marker-symbol/src/main/java/com/esri/samples/picture_marker_symbol/PictureMarkerSymbolSample.java

@@ -52,8 +52,7 @@ public class PictureMarkerSymbolSample extends Application {
   private PictureMarkerSymbol blueSymbol;
   private PictureMarkerSymbol orangeSymbol;
 
-  private static final String CAMPSITE_SYMBOL =
-      "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Recreation/FeatureServer/0/images/e82f744ebb069bb35b234b3fea46deae";
+  private static final String CAMPSITE_SYMBOL = "https://static.arcgis.com/images/Symbols/OutdoorRecreation/Camping.png";
 
   @Override
   public void start(Stage stage) {

symbology/render-multilayer-symbols/src/main/java/com/esri/samples/render_multilayer_symbols/RenderMultilayerSymbolsSample.java

@@ -100,8 +100,7 @@ public void start(Stage stage) {
 
       // create picture marker symbol from URI
       PictureMarkerSymbolLayer pictureMarkerFromUri = new PictureMarkerSymbolLayer((
-        "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Recreation/FeatureServer/0/images" +
-          "/e82f744ebb069bb35b234b3fea46deae"));
+        "https://static.arcgis.com/images/Symbols/OutdoorRecreation/Camping.png"));
 
       // wait for picture marker symbol to load before creating graphics from it
       pictureMarkerFromUri.addDoneLoadingListener(() -> {