Add to app measurement (#33458)

packages/flutter_tools/lib/src/project.dart

diff --git a/packages/flutter_tools/lib/src/project.dart b/packages/flutter_tools/lib/src/project.dart
index 60c8f12..46cec9b 100644
--- a/packages/flutter_tools/lib/src/project.dart
+++ b/packages/flutter_tools/lib/src/project.dart
@@ -397,6 +397,7 @@
   final FlutterProject parent;
 
   static final RegExp _applicationIdPattern = RegExp('^\\s*applicationId\\s+[\'\"](.*)[\'\"]\\s*\$');
+  static final RegExp _kotlinPluginPattern = RegExp('^\\s*apply plugin\:\\s+[\'\"]kotlin-android[\'\"]\\s*\$');
   static final RegExp _groupPattern = RegExp('^\\s*group\\s+[\'\"](.*)[\'\"]\\s*\$');
 
   /// The Gradle root directory of the Android host app. This is the directory
@@ -419,6 +420,12 @@
   /// True if the parent Flutter project is a module.
   bool get isModule => parent.isModule;
 
+  /// True, if the app project is using Kotlin.
+  bool get isKotlin {
+    final File gradleFile = hostAppGradleRoot.childDirectory('app').childFile('build.gradle');
+    return _firstMatchInFile(gradleFile, _kotlinPluginPattern) != null;
+  }
+
   File get appManifestFile {
     return isUsingGradle
         ? fs.file(fs.path.join(hostAppGradleRoot.path, 'app', 'src', 'main', 'AndroidManifest.xml'))