Add SecurityWarningIconUpdate field trial to the test bot config files

testing/variations/fieldtrial_testing_config_ios.json

 {
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillProfileCleanup": [
         {
             "enable_features": [
                 "AutofillProfileCleanup"
@@ skipping 62 matching lines @@
             "params": {
                 "delay_tcp_race": "true"
             }
         }
     ],
     "SdchPersistence": [
         {
             "group_name": "Enabled"
         }
     ],
+    "SecurityWarningIconUpdate": [
+        {
+            "enable_features": [
+                "SecurityWarningIconUpdate"
+            ],
+            "group_name": "Enabled"
+        },
+        {
+            "disable_features": [
+                "SecurityWarningIconUpdate"
+            ],
+            "group_name": "Control"
+        },
+        {
+            "group_name": "Default"
+        }
+    ],
     "SyncHttpContentCompression": [
         {
             "group_name": "Enabled"
         },
         {
             "group_name": "Disabled"
         }
     ],
     "TabSyncByRecency": [
         {
             "group_name": "Enabled"
         }
     ]
 }