Avoid generated plugin registrant warnings for scenario_app

testing/scenario_app/android/app/src/androidTest/java/dev/flutter/scenarios/EngineLaunchE2ETest.java

@@ -33,7 +33,13 @@ public void smokeTestEngineLaunch() throws Throwable {
     // Run the production under test on the UI thread instead of annotating the whole test
     // as @UiThreadTest because having the message handler and the CompletableFuture both being
     // on the same thread will create deadlocks.
-    UiThreadStatement.runOnUiThread(() -> engine.set(new FlutterEngine(applicationContext)));
+    UiThreadStatement.runOnUiThread(
+        () ->
+            engine.set(
+                new FlutterEngine(
+                    applicationContext,
+                    /*dartVmArgs */ null,
+                    /* automaticallyRegisterPlugins */ false)));
     SettableFuture<Boolean> statusReceived = SettableFuture.create();
 
     // Resolve locale to `en_US`.

testing/scenario_app/android/app/src/main/java/dev/flutter/scenarios/SpawnMultiEngineActivity.java

@@ -16,14 +16,16 @@ public class SpawnMultiEngineActivity extends TestActivity {
   @NonNull
   public FlutterEngine provideFlutterEngine(@NonNull Context context) {
     FlutterEngineGroup engineGroup = new FlutterEngineGroup(context);
-    FlutterEngine firstEngine = engineGroup.createAndRunDefaultEngine(context);
+    FlutterEngineGroup.Options options =
+        new FlutterEngineGroup.Options(context).setAutomaticallyRegisterPlugins(false);
+    FlutterEngine firstEngine = engineGroup.createAndRunEngine(options);
 
-    FlutterEngine secondEngine = engineGroup.createAndRunDefaultEngine(context);
+    FlutterEngine secondEngine = engineGroup.createAndRunEngine(options);
 
     // Check that a new engine can be spawned from the group even if the group's
     // original engine has been destroyed.
     firstEngine.destroy();
-    FlutterEngine thirdEngine = engineGroup.createAndRunDefaultEngine(context);
+    FlutterEngine thirdEngine = engineGroup.createAndRunEngine(options);
 
     return thirdEngine;
   }

testing/scenario_app/android/app/src/main/java/dev/flutter/scenarios/SpawnedEngineActivity.java

@@ -16,9 +16,11 @@ public class SpawnedEngineActivity extends TestActivity {
   @NonNull
   public FlutterEngine provideFlutterEngine(@NonNull Context context) {
     FlutterEngineGroup engineGroup = new FlutterEngineGroup(context);
-    engineGroup.createAndRunDefaultEngine(context);
+    FlutterEngineGroup.Options options =
+        new FlutterEngineGroup.Options(context).setAutomaticallyRegisterPlugins(false);
+    engineGroup.createAndRunEngine(options);
 
-    FlutterEngine secondEngine = engineGroup.createAndRunDefaultEngine(context);
+    FlutterEngine secondEngine = engineGroup.createAndRunEngine(options);
 
     secondEngine
         .getDartExecutor()