Initialize the AssetManager from the application context so that assets from dynamic feature modules can be loaded.

Author: chingjun

shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java

@@ -5,6 +5,8 @@
 package io.flutter.embedding.engine;
 
 import android.content.Context;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.res.AssetManager;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import io.flutter.FlutterInjector;
@@ -264,7 +266,13 @@ public FlutterEngine(
       @Nullable String[] dartVmArgs,
       boolean automaticallyRegisterPlugins,
       boolean waitForRestorationData) {
-    this.dartExecutor = new DartExecutor(flutterJNI, context.getAssets());
+    AssetManager assetManager;
+    try {
+      assetManager = context.createPackageContext(context.getPackageName(), 0).getAssets();
+    } catch (NameNotFoundException e) {
+      assetManager = context.getAssets();
+    }
+    this.dartExecutor = new DartExecutor(flutterJNI, assetManager);
     this.dartExecutor.onAttachedToJNI();
 
     accessibilityChannel = new AccessibilityChannel(dartExecutor, flutterJNI);