old_contents: DATABASES = {"default": {"ENGINE": "django.db.backends.sqlite3"}}
  
  SECRET_KEY = "secrekey"
  
  INSTALLED_APPS = ["phonenumber_field", "tests"]
  
new_contents: DATABASES = {"default": {"ENGINE": "django.db.backends.sqlite3"}}
  DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
  
  SECRET_KEY = "secrekey"
  
  INSTALLED_APPS = ["phonenumber_field", "tests"]
  
subject: Set DEFAULT_AUTO_FIELD for the test project