Add AutofillDoNotMigrateUnsupportedLocalCards to fieldtrial_testing_config

Server side config: https://critique.corp.google.com/#review/252708499

Bug: 954367
Change-Id: I68f8dbe9c3d97139f82e66a09f64d80ec860cf09
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1656051Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Sujie Zhu <sujiezhu@google.com>
Cr-Commit-Position: refs/heads/master@{#669029}

testing/variations/fieldtrial_testing_config.json

@@ -594,6 +594,24 @@
             ]
         }
     ],
+    "AutofillDoNotMigrateUnsupportedLocalCards": [
+        {
+            "platforms": [
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "AutofillDoNotMigrateUnsupportedLocalCards"
+                    ]
+                }
+            ]
+        }
+    ],
     "AutofillDoNotUploadSaveUnsupportedCards": [
         {
             "platforms": [