Short circuit v1 deprecation warning on plugin projects (#94769)

packages/flutter_tools/lib/src/project.dart

@@ -417,6 +417,9 @@ class AndroidProject extends FlutterProjectPlatform {
   /// True if the parent Flutter project is a module.
   bool get isModule => parent.isModule;
 
+  /// True if the parent Flutter project is a plugin.
+  bool get isPlugin => parent.isPlugin;
+
   /// True if the Flutter project is using the AndroidX support library.
   bool get usesAndroidX => parent.usesAndroidX;
 
@@ -595,6 +598,13 @@ The detected reason was:
       // only supports the V2 embedding.
       return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v2, 'Is add-to-app module');
     }
+    if (isPlugin) {
+      // Plugins do not use an appManifest, so we stop here.
+      //
+      // TODO(garyq): This method does not currently check for code references to
+      // the v1 embedding, we should check for this once removal is further along.
+      return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v2, 'Is plugin');
+    }
     if (appManifestFile == null || !appManifestFile.existsSync()) {
       return AndroidEmbeddingVersionResult(AndroidEmbeddingVersion.v1, 'No `${appManifestFile.absolute.path}` file');
     }

packages/flutter_tools/test/general.shard/project_test.dart

@@ -207,6 +207,13 @@ void main() {
         project.checkForDeprecation(deprecationBehavior: DeprecationBehavior.ignore);
         expect(testLogger.statusText, contains('https://flutter.dev/go/android-project-migration'));
       });
+      _testInMemory('Android plugin project does not throw v1 embedding deprecation warning', () async {
+        final FlutterProject project = await aPluginProject();
+
+        project.checkForDeprecation(deprecationBehavior: DeprecationBehavior.exit);
+        expect(testLogger.statusText, isNot(contains('https://flutter.dev/go/android-project-migration')));
+        expect(testLogger.statusText, isNot(contains('No `<meta-data android:name="flutterEmbedding" android:value="2"/>` in ')));
+      });
       _testInMemory('Android plugin without example app does not show a warning', () async {
         final FlutterProject project = await aPluginProject();
         project.example.directory.deleteSync();