Enable DRP config service by default

testing/variations/fieldtrial_testing_config_ios.json

 {
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillProfileOrderByFrecency": [
         {
             "group_name": "EnabledLimitTo3",
             "params": {
@@ skipping 10 matching lines @@
         }
     ],
     "DataCompressionProxyDevRollout": [
         {
             "group_name": "Control"
         },
         {
             "group_name": "Enabled"
         }
     ],
-    "DataReductionProxyConfigService": [
-        {
-            "group_name": "Enabled",
-            "params": {
-                "minimum_refresh_interval_on_success_msec": "21600000"
-            }
-        }
-    ],
     "PageRevisitInstrumentation": [
         {
             "group_name": "Enabled"
         }
     ],
     "PasswordBranding": [
         {
             "group_name": "SmartLockBrandingSavePromptOnly"
         }
     ],
@@ skipping 22 matching lines @@
     ],
     "VarationsServiceControl": [
         {
             "group_name": "Interval_30min",
             "params": {
                 "fetch_period_min": "30"
             }
         }
     ]
 }