Fix lints: unnecessary_brace_in_string_interp

pkg/analysis_server/lib/src/context_manager.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library context.directory.manager;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:core' hide Resource;
@@ skipping 1548 matching lines @@
 }
 
 /**
  * Concrete [FolderDisposition] object indicating that the context for a given
  * folder should resolve packages using a ".packages" file.
  */
 class PackagesFileDisposition extends FolderDisposition {
   @override
   final Packages packages;
 
-  PackagesFileDisposition(this.packages) {}
+  PackagesFileDisposition(this.packages);
 
   @override
   String get packageRoot => null;
 
   Map<String, List<Folder>> buildPackageMap(ResourceProvider resourceProvider) {
     Map<String, List<Folder>> packageMap = <String, List<Folder>>{};
     if (packages == null) {
       return packageMap;
     }
     packages.asMap().forEach((String name, Uri uri) {
@@ skipping 10 matching lines @@
       ResourceProvider resourceProvider) {
     if (packages != null) {
       // Construct package map for the SdkExtUriResolver.
       Map<String, List<Folder>> packageMap = buildPackageMap(resourceProvider);
       return <UriResolver>[new SdkExtUriResolver(packageMap)];
     } else {
       return const <UriResolver>[];
     }
   }
 }