Change log for ZSCALER_ZPA

Date Changes
2026-01-07 - Updated the field mapping for the Zscaler ZPA parser.
- Please refer to the parser documentation page for information regarding the updated UDM mappings - https://docs.cloud.google.com/chronicle/docs/ingestion/default-parsers/zscaler-zpa#udm_mapping_delta
2025-11-28 - additional.fields[protocol_version]: Newly mapped `ProtocolVersion` raw log field with `additional.fields[protocol_version]` UDM field.
- principal.user.userid: Newly mapped `UserID` raw log field with `principal.user.userid` UDM field, if the value of `InternalReason` raw log field is not equal to `ZPN_STATUS_AUTHENTICATED` or `ZPN_STATUS_DISCONNECTED`.
- principal.user.user_display_name: Newly mapped `UserID` raw log field with `principal.user.user_display_name` UDM field, if the value of `InternalReason` raw log field is not equal to `ZPN_STATUS_AUTHENTICATED` or `ZPN_STATUS_DISCONNECTED`.
- principal.user.email_addresses: Newly mapped `UserID` raw log field with `principal.user.email_addresses` UDM field, if the value of `InternalReason` raw log field is not equal to `ZPN_STATUS_AUTHENTICATED` or `ZPN_STATUS_DISCONNECTED`.
- target.user.userid: Newly mapped `UserID` raw log field with `target.user.userid` UDM field, if the value of `InternalReason` raw log field is equal to `ZPN_STATUS_AUTHENTICATED` or `ZPN_STATUS_DISCONNECTED`.
- target.user.user_display_name: Newly mapped `UserID` raw log field with `target.user.user_display_name` UDM field, if the value of `InternalReason` raw log field is equal to `ZPN_STATUS_AUTHENTICATED` or `ZPN_STATUS_DISCONNECTED`.
- target.user.email_addresses: Newly mapped `UserID` raw log field with `target.user.email_addresses` UDM field, if the value of `InternalReason` raw log field is equal to `ZPN_STATUS_AUTHENTICATED` or `ZPN_STATUS_DISCONNECTED`.
2025-11-14 - target.hostname: Modified mapping for the `Host` raw log field. When the value is an IP address, it is now mapped to `target.ip` and no longer to `target.hostname` and `target.asset.hostname`. When the value is not an IP address, it remains mapped to `target.hostname` and `target.asset.hostname`.
2025-10-30 Modified the value mapping logic for the `security_result.action` UDM field to correct an issue where events were too often marked as `BLOCK`.
- security_result.action: Removed the condition that set the value of `security_result.action` UDM field based on the value of `ConnectionStatus` raw log field.
- security_result.action: Modified the codition to set the value of `security_result.action` UDM field based on the value of `InternalReason` raw log field. The value of `security_result.action` UDM field set to `BLOCK` only if the value of `InternalReason` raw log field is one of the following: `BRK_MT_SETUP_FAIL_NO_POLICY_FOUND`, `BRK_MT_SETUP_FAIL_REJECTED_BY_POLICY`, or `BRK_MT_SETUP_FAIL_SAML_EXPIRED`. The value of `security_result.action` UDM field set to `ALLOW` for all other values of `InternalReason` raw log field.
2025-05-08 - Promoted ZSCALER_ZPA Premium parser to default. You can see full details in the parser configuration page - https://cloud.google.com/chronicle/docs/ingestion/default-parsers/ingest-zscaler-logs