Remove flutterBuildPluginAsAarFeature flag (#46101)

packages/flutter_tools/lib/src/features.dart

@@ -73,7 +73,6 @@ const List<Feature> allFeatures = <Feature>[
   flutterLinuxDesktopFeature,
   flutterMacOSDesktopFeature,
   flutterWindowsDesktopFeature,
-  flutterBuildPluginAsAarFeature,
   flutterAndroidEmbeddingV2Feature,
   flutterWebIncrementalCompiler,
 ];
@@ -134,16 +133,6 @@ const Feature flutterWindowsDesktopFeature = Feature(
   ),
 );
 
-/// The [Feature] for building plugins as AARs in an app project.
-const Feature flutterBuildPluginAsAarFeature = Feature(
-  name: 'Build plugins independently as AARs in app projects',
-  configSetting: 'enable-build-plugin-as-aar',
-  master: FeatureChannelSetting(
-    available: true,
-    enabledByDefault: false,
-  ),
-);
-
 /// The [Feature] for generating projects using the new Android embedding.
 const Feature flutterAndroidEmbeddingV2Feature = Feature(
   name: 'flutter create generates projects using the Android embedding V2',