Fix telemetry image option logic

Author: jiapinw

src/sagemaker/serve/builder/model_builder.py

@@ -605,7 +605,7 @@ def build(
 
         self.serve_settings = self._get_serve_setting()
 
-        self._is_custom_image_uri = self.image_uri is None
+        self._is_custom_image_uri = self.image_uri is not None
 
         if isinstance(self.model, str):
             if self._is_jumpstart_model_id():