Change the mobile device ids from enum to string (#323)

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": "2024-10-03 16:37:45.451174",
-            "spec_repo_commit": "ef194005"
+            "regenerated": "2024-10-04 10:38:16.608195",
+            "spec_repo_commit": "7a63d530"
         },
         "v2": {
             "apigentools_version": "1.6.6",
-            "regenerated": "2024-10-03 16:37:45.467537",
-            "spec_repo_commit": "ef194005"
+            "regenerated": "2024-10-04 10:38:16.622752",
+            "spec_repo_commit": "7a63d530"
         }
     }
 }