Skip flaky test (expression_evaluation_test) (#19543)

packages/flutter_tools/test/integration/expression_evaluation_test.dart

@@ -6,7 +6,6 @@ import 'dart:async';
 
 import 'package:file/file.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
-import 'package:flutter_tools/src/base/platform.dart';
 import 'package:test/test.dart';
 import 'package:vm_service_client/vm_service_client.dart';
 
@@ -111,5 +110,7 @@ void main() {
       await evaluateComplexReturningExpressions();
     });
     // https://github.com/flutter/flutter/issues/17833
-  }, timeout: const Timeout.factor(3), skip: platform.isWindows);
+    // The test appears to be flaky and time out some times, skipping while
+    // investigation is ongoing: https://github.com/flutter/flutter/issues/19542
+  }, timeout: const Timeout.factor(3), skip: true);
 }