feat: Add a new option eval_storage_uri in adk web & adk eval to specify GCS bucket to store eval data

PiperOrigin-RevId: 774947795

src/google/adk/evaluation/gcs_eval_sets_manager.py

@@ -72,6 +72,13 @@ class GcsEvalSetsManager(EvalSetsManager):
           f"Invalid {id_name}. {id_name} should have the `{pattern}` format",
       )
 
+  def _load_eval_set_from_blob(self, blob_name: str) -> Optional[EvalSet]:
+    blob = self.bucket.blob(blob_name)
+    if not blob.exists():
+      return None
+    eval_set_data = blob.download_as_text()
+    return EvalSet.model_validate_json(eval_set_data)
+
   def _write_eval_set_to_blob(self, blob_name: str, eval_set: EvalSet):
     """Writes an EvalSet to GCS."""
     blob = self.bucket.blob(blob_name)
@@ -88,11 +95,7 @@ class GcsEvalSetsManager(EvalSetsManager):
   def get_eval_set(self, app_name: str, eval_set_id: str) -> Optional[EvalSet]:
     """Returns an EvalSet identified by an app_name and eval_set_id."""
     eval_set_blob_name = self._get_eval_set_blob_name(app_name, eval_set_id)
-    blob = self.bucket.blob(eval_set_blob_name)
-    if not blob.exists():
-      return None
-    eval_set_data = blob.download_as_text()
-    return EvalSet.model_validate_json(eval_set_data)
+    return self._load_eval_set_from_blob(eval_set_blob_name)
 
   @override
   def create_eval_set(self, app_name: str, eval_set_id: str):