feat: standardize configuration fields across all evaluation examples

- Add `fixed_ip` field to all 369 JSON files in examples directory
  - Set to `true` for 8 files listed in google_chrome.json multi_apps
  - Set to `false` for remaining 361 files
- Add `possibility_of_env_change` field to 363 JSON files missing this field
  - Set to "low" for newly added fields
  - Preserve existing values (4 medium, 2 high) for 6 files that already had this field

This ensures consistent configuration schema across all evaluation examples
while maintaining backward compatibility with existing settings.

evaluation_examples/examples/vs_code/971cbb5b-3cbf-4ff7-9e24-b5c84fcebfa6.json

@@ -26,5 +26,7 @@
   "evaluator": {
     "func": "infeasible"
   },
-  "proxy": false
+  "proxy": false,
+  "fixed_ip": false,
+  "possibility_of_env_change": "low"
 }