remove duplicate packages in fuzz test

pkg/analysis_server/bin/fuzz/server_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 server.manager;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:matcher/matcher.dart';
-
-import 'byte_stream_channel.dart';
-import 'channel.dart';
-import 'protocol.dart';
+import 'package:analysis_server/src/protocol.dart';
+import 'package:analysis_server/src/channel/channel.dart';
+import 'package:analysis_server/src/channel/byte_stream_channel.dart';
 
 part 'logging_client_channel.dart';
 
 /**
  * The results returned by [ServerManager].analyze(...) once analysis
  * has finished.
  */
 class AnalysisResults {
   Duration elapsed;
   int errorCount = 0;
@@ skipping 330 matching lines @@
   }
 
   /**
    * Launch analysis server in a separate process
    * and return a future with a manager for that analysis server.
    */
   static Future<ServerManager> start(String serverPath) {
     return new ServerManager()._launchServer(serverPath);
   }
 }