Change the integration_test structure to be compliant with the official guidelines

Author: tugorez

packages/file_selector/file_selector_web/integration_test/test_driver/dom_helper_integration.dart renamed to packages/file_selector/file_selector_web/integration_test/dom_helper_test.dart

@@ -1,10 +1,11 @@
 #!/usr/bin/bash
+
 if pgrep -lf chromedriver > /dev/null; then
   echo "chromedriver is running."
 
   if [ $# -eq 0 ]; then
     echo "No target specified, running all tests..."
-    find test_driver/ -iname *_integration.dart | xargs -n1 -i -t flutter drive -d web-server --web-port=7357 --browser-name=chrome --target='{}'
+    find integration_test/ -iname *_test.dart | xargs -n1 -i -t flutter drive -d web-server --web-port=7357 --browser-name=chrome  --driver=test_driver/integration_test.dart --target='{}'
   else
     echo "Running test target: $1..."
     set -x

packages/file_selector/file_selector_web/integration_test/test_driver/file_selector_web_integration.dart renamed to packages/file_selector/file_selector_web/integration_test/file_selector_web_test.dart

@@ -1,7 +1,6 @@
 // Copyright 2020 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-
 import 'package:integration_test/integration_test_driver.dart';
 
-Future<void> main() async => integrationDriver();
+Future<void> main() => integrationDriver();