Enum describing possible user list crm data source type.

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

| Enums ||
|---|---|
| ## `FIRST_PARTY` | The uploaded data is first-party data. |
| ## `THIRD_PARTY_CREDIT_BUREAU` | The uploaded data is from a third-party credit bureau. |
| ## `THIRD_PARTY_PARTNER_DATA` | The uploaded data is third party partner data. |
| ## `THIRD_PARTY_VOTER_FILE` | The uploaded data is from a third-party voter file. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |