Support materializing Flutter module host app on iOS (#21276)

* Prototype

* Fix paths to Flutter library resources

* Invoke pod install as necessary for materialized modules

* Add devicelab test for module use on iOS

* Remove debug output

* Rebase, reame materialize editable

* Add devicelab test editable iOS host app

* Removed add2app test section
diff --git a/packages/flutter_tools/test/ios/cocoapods_test.dart b/packages/flutter_tools/test/ios/cocoapods_test.dart
index 435bb96..a69b5ac 100644
--- a/packages/flutter_tools/test/ios/cocoapods_test.dart
+++ b/packages/flutter_tools/test/ios/cocoapods_test.dart
@@ -46,7 +46,7 @@
     mockProcessManager = MockProcessManager();
     mockXcodeProjectInterpreter = MockXcodeProjectInterpreter();
     projectUnderTest = await FlutterProject.fromDirectory(fs.directory('project'));
-    projectUnderTest.ios.directory.childDirectory('Runner.xcodeproj').createSync(recursive: true);
+    projectUnderTest.ios.xcodeProject.createSync(recursive: true);
     cocoaPodsUnderTest = CocoaPods();
     pretendPodVersionIs('1.5.0');
     fs.file(fs.path.join(