Enable DRP config service by default

testing/variations/fieldtrial_testing_config_mac.json

 {
     "AutofillClassifier": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
@@ skipping 31 matching lines @@
         },
         {
             "group_name": "Default"
         }
     ],
     "ChromotingQUIC": [
         {
             "group_name": "Enabled"
         }
     ],
-    "DataReductionProxyConfigService": [
-        {
-            "group_name": "Enabled",
-            "params": {
-                "minimum_refresh_interval_on_success_msec": "21600000"
-            }
-        }
-    ],
     "EnableGoogleCachedCopyTextExperiment": [
         {
             "group_name": "Button"
         }
     ],
     "ExtensionActionRedesign": [
         {
             "group_name": "Enabled"
         }
     ],
@@ skipping 197 matching lines @@
     ],
     "use-new-media-cache": [
         {
             "enable_features": [
                 "use-new-media-cache"
             ],
             "group_name": "Enabled"
         }
     ]
 }