chore(main): release google-ads-data_manager-v1 0.4.0 (#33972)

* chore(main): release google-ads-data_manager-v1 0.4.0

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: release-please[bot]

.release-please-manifest.json

@@ -5,7 +5,7 @@
   "google-ads-ad_manager-v1+FILLER": "0.0.0",
   "google-ads-data_manager": "0.3.0",
   "google-ads-data_manager+FILLER": "0.0.0",
-  "google-ads-data_manager-v1": "0.3.0",
+  "google-ads-data_manager-v1": "0.4.0",
   "google-ads-data_manager-v1+FILLER": "0.0.0",
   "google-ads-marketing_platform-admin": "0.2.0",
   "google-ads-marketing_platform-admin+FILLER": "0.0.0",

google-ads-data_manager-v1/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+### 0.4.0 (2026-05-19)
+
+#### Features
+
+* add the coupon_codes field to CartData to track coupon redemptions for Google Ads and Google Analytics ([#33971](https://github.com/googleapis/google-cloud-ruby/issues/33971)) 
+
 ### 0.3.0 (2026-05-06)
 
 ### ⚠ BREAKING CHANGES

google-ads-data_manager-v1/lib/google/ads/data_manager/v1/version.rb

@@ -21,7 +21,7 @@ module Google
   module Ads
     module DataManager
       module V1
-        VERSION = "0.3.0"
+        VERSION = "0.4.0"
       end
     end
   end

google-ads-data_manager-v1/snippets/snippet_metadata_google.ads.datamanager.v1.json

@@ -1,7 +1,7 @@
 {
   "client_library": {
     "name": "google-ads-data_manager-v1",
-    "version": "0.3.0",
+    "version": "0.4.0",
     "language": "RUBY",
     "apis": [
       {