fix(api): add support for "image" icon when duplicate app (#20744) (#20761)

api/services/app_dsl_service.py

 
         # Set icon type
         icon_type_value = icon_type or app_data.get("icon_type")
-        if icon_type_value in ["emoji", "link"]:
+        if icon_type_value in ["emoji", "link", "image"]:
             icon_type = icon_type_value
         else:
             icon_type = "emoji"