Retention campaign goal settings.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/common/campaign_goal_settings.proto)

| Fields ||
|---|---|
| ## `target_option` | `https://developers.google.com/google-ads/api/reference/rpc/v26/CustomerLifecycleOptimizationModeEnum.CustomerLifecycleOptimizationMode` Retention goal optimization mode for this campaign. Defaults to TARGET_ALL. Only customers on the allowlist can set target_option. |
| ## `value_settings_override` | `https://developers.google.com/google-ads/api/reference/rpc/v26/CustomerLifecycleOptimizationValueSettings` Retention goal campaign specific value settings. |