Update arcgis_maps dependency to 200.8 (#326)

Author: PaulAllanSturm

pubspec.yaml

@@ -8,7 +8,7 @@ environment:
   sdk: '>=3.8.1 <4.0.0'
 
 dependencies:
-  arcgis_maps: ^200.7.0
+  arcgis_maps: ^200.8.0
   async: ^2.12.0
   build: ^2.4.2
   build_config: ^1.1.2