Fix service class in cost_surface sample

Author: nanaeaubry

samples/04_gis_analysts_data_scientists/calculating_cost_surfaces_using_weighted_overlay_analysis.ipynb

@@ -51,7 +51,7 @@
    "source": [
     "# import GIS from the arcgis.gis module\n",
     "from arcgis.gis import GIS\n",
-    "from arcgis.features import FeatureLayer"
+    "from arcgis.layers import Service"
    ]
   },
   {
@@ -186,7 +186,7 @@
    "source": [
     "# Access the USA States item from the Living Atlas using the item id value\n",
     "url = 'https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/USA_States_Generalized/FeatureServer/0'\n",
-    "states_lyr = FeatureLayer(url)\n",
+    "states_lyr = Service(url)\n",
     "states_lyr"
    ]
   },
@@ -764,10 +764,10 @@
    "source": [
     "# Create a map to display the persistent analysis result in a map\n",
     "map1 = gis.map('State of Washington, USA')\n",
-    "map1.add_layer(search_persistent_result)\n",
+    "map1.content.add(search_persistent_result)\n",
     "# Create a map to display the dynamic analysis result in another map.\n",
     "map2 = gis.map('State of Washington, USA')\n",
-    "map2.add_layer(result_weighted_overlay)"
+    "map2.content.add(result_weighted_overlay)"
    ]
   },
   {