Enable Template with Bridgeless (#39661)

Summary:
Pull Request resolved: react/react-native#39661

Changelog:
[Android][Changed] - Enable Template with Bridgeless

Reviewed By: cortinico

Differential Revision: D49464580

fbshipit-source-id: 26dd8e2a0b9a66421d58f147eed4d2fd28817dc7

Original-Commit: react/react-native@8b2f324

Author: Lulu Wu

template/template/android/app/src/main/java/com/helloworld/MainApplication.kt

@@ -5,11 +5,15 @@ import com.facebook.react.PackageList
 import com.facebook.react.ReactApplication
 import com.facebook.react.ReactNativeHost
 import com.facebook.react.ReactPackage
+import com.facebook.react.common.annotations.UnstableReactNativeAPI
 import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint.load
+import com.facebook.react.defaults.DefaultReactHost
 import com.facebook.react.defaults.DefaultReactNativeHost
 import com.facebook.react.flipper.ReactNativeFlipper
+import com.facebook.react.interfaces.ReactHost
 import com.facebook.soloader.SoLoader
 
+@UnstableReactNativeAPI
 class MainApplication : Application(), ReactApplication {
 
   override val reactNativeHost: ReactNativeHost =
@@ -28,6 +32,14 @@ class MainApplication : Application(), ReactApplication {
         override val isHermesEnabled: Boolean = BuildConfig.IS_HERMES_ENABLED
       }
 
+  override val reactHost: ReactHost
+    get() =
+        DefaultReactHost.getDefaultReactHost(
+            context = this,
+            packageList = PackageList(this).packages,
+            jsMainModulePath = "index",
+            isHermesEnabled = BuildConfig.IS_HERMES_ENABLED)
+
   override fun onCreate() {
     super.onCreate()
     SoLoader.init(this, false)