Add account on demand and committed usage to billable summary (#29991)

Co-authored-by: ci.datadog-api-spec <[email protected]>

Author: api-clients-generation-pipeline[bot]

.apigentools-info

@@ -4,13 +4,13 @@
     "spec_versions": {
         "v1": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2025-07-21 08:52:23.791564",
-            "spec_repo_commit": "eea03ed3"
+            "regenerated": "2025-07-21 13:56:36.540795",
+            "spec_repo_commit": "06ccc326"
         },
         "v2": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2025-07-21 08:52:33.004216",
-            "spec_repo_commit": "eea03ed3"
+            "regenerated": "2025-07-21 13:56:45.594812",
+            "spec_repo_commit": "06ccc326"
         }
     }
 }