fix: resolve path parameter extraction for complex Google API endpoints

Fixes #1814

- Fix GoogleApiToOpenApiConverter to properly handle path parameters in
  complex endpoints like /v1/documents/{documentId}:batchUpdate
- Trust Google Discovery Document 'location' field over URL parsing
- Add comprehensive test suite for Google Docs batchUpdate functionality
- Verify parameter location handling for complex endpoint patterns
- Test schema validation for BatchUpdateDocumentRequest/Response

Author: Alec-Ellebracht

src/google/adk/tools/google_api_tool/googleapi_to_openapi_converter.py

@@ -391,9 +391,11 @@ def _convert_operation(
       if param_name in path_params:
         continue
 
+      location = param_data.get("location", "query")
+      
       param = {
           "name": param_name,
-          "in": "query",
+          "in": location,
           "description": param_data.get("description", ""),
           "required": param_data.get("required", False),
           "schema": self._convert_parameter_schema(param_data),