Refactor customer_testing (#145911)

Refactor customer_testing suite in order to reduce testing logic in test.dart and allow for later implementing package:test onto the existing customer_testing tests

Part of https://github.com/flutter/flutter/issues/145482

*If you had to change anything in the [flutter/tests] repo, include a link to the migration guide as per the [breaking change policy].*

dev/bots/suite_runners/run_customer_testing_tests.dart

@@ -0,0 +1,51 @@
+// Copyright 2014 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 'dart:io' show Platform;
+
+import 'package:path/path.dart' as path;
+
+import '../run_command.dart';
+import '../utils.dart';
+
+Future<void> customerTestingRunner(String flutterRoot) async {
+  printProgress('${green}Running customer testing$reset');
+  await runCommand(
+    'git',
+    const <String>[
+      'fetch',
+      'origin',
+      'master',
+    ],
+    workingDirectory: flutterRoot,
+  );
+  await runCommand(
+    'git',
+    const <String>[
+      'branch',
+      '-f',
+      'master',
+      'origin/master',
+    ],
+    workingDirectory: flutterRoot,
+  );
+  final Map<String, String> env = Platform.environment;
+  final String? revision = env['REVISION'];
+  if (revision != null) {
+    await runCommand(
+      'git',
+      <String>[
+        'checkout',
+        revision,
+      ],
+      workingDirectory: flutterRoot,
+    );
+  }
+  final String winScript = path.join(flutterRoot, 'dev', 'customer_testing', 'ci.bat');
+  await runCommand(
+    Platform.isWindows? winScript: './ci.sh',
+    <String>[],
+    workingDirectory: path.join(flutterRoot, 'dev', 'customer_testing'),
+  );
+}

dev/bots/test.dart

@@ -66,6 +66,7 @@ import 'package:process/process.dart';
 import 'run_command.dart';
 import 'suite_runners/run_add_to_app_life_cycle_tests.dart';
 import 'suite_runners/run_analyze_tests.dart';
+import 'suite_runners/run_customer_testing_tests.dart';
 import 'suite_runners/run_docs_tests.dart';
 import 'suite_runners/run_flutter_packages_tests.dart';
 import 'suite_runners/run_realm_checker_tests.dart';
@@ -253,7 +254,7 @@ Future<void> main(List<String> args) async {
       'flutter_plugins': () => flutterPackagesRunner(flutterRoot),
       'skp_generator': skpGeneratorTestsRunner,
       'realm_checker': () => realmCheckerTestRunner(flutterRoot),
-      'customer_testing': _runCustomerTesting,
+      'customer_testing': () => customerTestingRunner(flutterRoot),
       'analyze': () => analyzeRunner(flutterRoot),
       'fuchsia_precache': _runFuchsiaPrecache,
       'docs': () => docsRunner(flutterRoot),
@@ -1198,48 +1199,6 @@ Future<void> _runWebUnitTests(String webRenderer, bool useWasm) async {
   await selectSubshard(subshards);
 }
 
-// Runs customer_testing.
-Future<void> _runCustomerTesting() async {
-  printProgress('${green}Running customer testing$reset');
-  await runCommand(
-    'git',
-    <String>[
-      'fetch',
-      'origin',
-      'master',
-    ],
-    workingDirectory: flutterRoot,
-  );
-  await runCommand(
-    'git',
-    <String>[
-      'branch',
-      '-f',
-      'master',
-      'origin/master',
-    ],
-    workingDirectory: flutterRoot,
-  );
-  final Map<String, String> env = Platform.environment;
-  final String? revision = env['REVISION'];
-  if (revision != null) {
-    await runCommand(
-      'git',
-      <String>[
-        'checkout',
-        revision,
-      ],
-      workingDirectory: flutterRoot,
-    );
-  }
-  final String winScript = path.join(flutterRoot, 'dev', 'customer_testing', 'ci.bat');
-  await runCommand(
-    Platform.isWindows? winScript: './ci.sh',
-    <String>[],
-    workingDirectory: path.join(flutterRoot, 'dev', 'customer_testing'),
-  );
-}
-
 // Runs flutter_precache.
 Future<void> _runFuchsiaPrecache() async {
   printProgress('${green}Running flutter precache tests$reset');