Fix repr

Author: samruds

src/sagemaker/serve/builder/schema_builder.py

@@ -216,6 +216,12 @@ def __repr__(self):
                 f"input_deserializer={self.input_deserializer._deserializer}\n"
                 f"output_deserializer={self.output_deserializer._deserializer})"
             )
+        elif hasattr(self, "custom_input_translator") and hasattr(self, "custom_output_translator"):
+            return (
+                f"SchemaBuilder(\n"
+                f"custom_input_translator={self.custom_input_translator}\n"
+                f"custom_output_translator={self.custom_output_translator}\n"
+            )
 
     def generate_marshalling_map(self) -> dict:
         """Generate marshalling map for the schema builder"""