Change variations service domain for Android Chrome.

testing/variations/fieldtrial_testing_config_mac.json

 {
     "AutofillClassifier": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
@@ skipping 423 matching lines @@
         {
             "group_name": "none"
         },
         {
             "group_name": "normal"
         },
         {
             "group_name": "aggressive"
         }
     ],
-    "VarationsServiceControl": [
-        {
-            "group_name": "Interval_30min",
-            "params": {
-                "fetch_period_min": "30"
-            }
-        }
-    ],
     "ViewsSimplifiedFullscreenUI": [
         {
             "enable_features": [
                 "ViewsSimplifiedFullscreenUI"
             ],
             "group_name": "Enabled"
         }
     ],
     "WebFontsInterventionV2": [
         {
@@ skipping 28 matching lines @@
     ],
     "use-new-media-cache": [
         {
             "enable_features": [
                 "use-new-media-cache"
             ],
             "group_name": "Enabled"
         }
     ]
 }