Add field trial testing config for ios cellular uma change

Bug: 1154678
Change-Id: Ib1f440dbba8b5cd2f8c5f7d580ba90e31cce9d1c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2845109
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Robert Kaplow <rkaplow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#875183}
GitOrigin-RevId: bcd443866b0bef5dcb0febd6b3638d3577ed8333
diff --git a/variations/fieldtrial_testing_config.json b/variations/fieldtrial_testing_config.json
index 22c1773..9697ae5 100644
--- a/variations/fieldtrial_testing_config.json
+++ b/variations/fieldtrial_testing_config.json
@@ -3213,6 +3213,21 @@
             ]
         }
     ],
+    "FixUmaCellularMetricsRecording": [
+        {
+            "platforms": [
+                "ios"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "FixUmaCellularMetricsRecording"
+                    ]
+                }
+            ]
+        }
+    ],
     "ForceSynchronousHTMLParsing": [
         {
             "platforms": [