Change the mobile device ids from enum to string (#2511)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

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

.apigentools-info

@@ -4,13 +4,13 @@
     "spec_versions": {
         "v1": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2024-10-03 16:37:49.298520",
-            "spec_repo_commit": "ef194005"
+            "regenerated": "2024-10-04 10:38:24.095988",
+            "spec_repo_commit": "7a63d530"
         },
         "v2": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2024-10-03 16:37:49.315729",
-            "spec_repo_commit": "ef194005"
+            "regenerated": "2024-10-04 10:38:24.110677",
+            "spec_repo_commit": "7a63d530"
         }
     }
 }