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: goldylocks87

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

@@ -393,7 +393,7 @@ def _convert_operation(
 
       param = {
           "name": param_name,
-          "in": "query",
+          "in": param_data.get("location", "query"),
           "description": param_data.get("description", ""),
           "required": param_data.get("required", False),
           "schema": self._convert_parameter_schema(param_data),