(TBR) Fix more failing tests

pkg/analysis_server/test/analysis/notification_errors_test.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 test.analysis.notification_errors;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 36 matching lines @@
 import 'does_not_exist.dart';
 ''');
     await waitForTasksFinished();
     List<AnalysisError> errors = filesErrors[testFile];
     // Verify that we are generating only 1 error for the bad URI.
     // https://github.com/dart-lang/sdk/issues/23754
     expect(errors, hasLength(1));
     AnalysisError error = errors[0];
     expect(error.severity, AnalysisErrorSeverity.ERROR);
     expect(error.type, AnalysisErrorType.COMPILE_TIME_ERROR);
-    expect(error.message, startsWith('Target of URI does not exist'));
+    expect(error.message, startsWith("Target of URI doesn't exist"));
   }
 
   test_lintError() async {
     var camelCaseTypesLintName = 'camel_case_types';
 
     addFile(
         '$projectPath/.analysis_options',
         '''
 linter:
   rules:
@@ skipping 60 matching lines @@
 }
 ''');
     await waitForTasksFinished();
     List<AnalysisError> errors = filesErrors[testFile];
     expect(errors, hasLength(1));
     AnalysisError error = errors[0];
     expect(error.severity, AnalysisErrorSeverity.WARNING);
     expect(error.type, AnalysisErrorType.STATIC_WARNING);
   }
 }