Merge pull request #7064 from segmentio/braze-syncmode

Add V2 Actions Callout to Braze Cloud Actions Docs

Author: pwseg

src/connections/destinations/catalog/actions-braze-cloud/index.md

@@ -34,6 +34,9 @@ Braze Cloud Mode (Actions) provides the following benefit over Braze Classic:
 > info ""
 > Braze requires that you include a `userId` or `braze_id` for all calls made in cloud-mode. Segment sends a `braze_id` if the `userId` is missing. When you use a device-mode connection, Braze automatically tracks anonymous activity using the `braze_id` if a `userId` is missing.
 
+> info "V2 Actions"
+> The V2 versions of each action include improved sync mode support. Only valid sync modes for each action are available. As a result, the `_update_existing_only` parameter is tied to the sync mode you select for the mapping. If you select the `update` sync mode, Segment passes `_update_existing_only: true` to Braze, and if you choose the `add` sync mode, Segment passes `_update_existing_only: false` to Braze.
+
 {% include components/actions-fields.html settings="true"%}
 
 ## Migration from Braze Classic