Add the ability to whitelist plugins

pkg/analysis_server/test/src/plugin/plugin_manager_test.dart

Index: pkg/analysis_server/test/src/plugin/plugin_manager_test.dart
diff --git a/pkg/analysis_server/test/src/plugin/plugin_manager_test.dart b/pkg/analysis_server/test/src/plugin/plugin_manager_test.dart
index 0990dd56a8bb2b03e6baec54d5b16b37e1546bc0..0213208033946bcb592522bc74c9cee955991ae9 100644
--- a/pkg/analysis_server/test/src/plugin/plugin_manager_test.dart
+++ b/pkg/analysis_server/test/src/plugin/plugin_manager_test.dart
@@ -187,6 +187,7 @@ class PluginManagerFromDiskTest extends PluginTestSupport {
     super.setUp();
     manager = new PluginManager(resourceProvider, byteStorePath, '',
         notificationManager, InstrumentationService.NULL_SERVICE);
+    manager.whitelistEverything();
   }
 
   test_addPluginToContextRoot() async {