Simplify the default browser infobar.

testing/variations/fieldtrial_testing_config_win.json

 {
     "AutofillClassifier": [
         {
             "group_name": "Enabled"
         }
     ],
     "AutofillFieldMetadata": [
         {
             "group_name": "Enabled"
         }
@@ skipping 41 matching lines @@
         },
         {
             "group_name": "Default"
         }
     ],
     "ChromotingQUIC": [
         {
             "group_name": "Enabled"
         }
     ],
+    "DefaultBrowserInfobar": [
+        {
+            "group_name": "SettingsText"
+        }
+    ],
     "DocumentWriteEvaluator": [
         {
             "enable_features": [
                 "DocumentWriteEvaluator"
             ],
             "group_name": "Enabled"
         }
     ],
     "EnableGoogleCachedCopyTextExperiment": [
         {
@@ skipping 289 matching lines @@
     ],
     "use-new-media-cache": [
         {
             "enable_features": [
                 "use-new-media-cache"
             ],
             "group_name": "Enabled"
         }
     ]
 }