(TBR) Fix more failing tests

pkg/analysis_server/test/analysis/notification_errors_test.dart

Index: pkg/analysis_server/test/analysis/notification_errors_test.dart
diff --git a/pkg/analysis_server/test/analysis/notification_errors_test.dart b/pkg/analysis_server/test/analysis/notification_errors_test.dart
index 318466567ac148162af56d5beade945061e9d715..8ab02c39e482b2c35b2575783696f5844c7b8b30 100644
--- a/pkg/analysis_server/test/analysis/notification_errors_test.dart
+++ b/pkg/analysis_server/test/analysis/notification_errors_test.dart
@@ -54,7 +54,7 @@ import 'does_not_exist.dart';
     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 {