Fix new arch example not render in RNTester (#39810)

Summary:
Pull Request resolved: #39810

Two issues will be fixed:
- Bridgeless has lazy view manager loading by default so the React Package that provides view managers must implement ViewManagerOnDemandReactPackage, we might could refactor the design of package classes later
- ThemedReactContext should **NOT** be used directly to call function ```getJSModule```, since it doesn't overrides ```getJSModule``` for Bridgeless, we can use it's internal variable ```meactApplicationContext``` which should be an instance of BridgelessReactContext

Reviewed By: cortinico

Differential Revision: D49912656

fbshipit-source-id: a0bdd717612398e8d7a6f36d36dba241a3b06bd7

Author: Lulu Wu

packages/rn-tester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterReactHostDelegate.kt

@@ -14,6 +14,7 @@ import com.facebook.react.JSEngineResolutionAlgorithm
 import com.facebook.react.ReactPackage
 import com.facebook.react.ReactPackageTurboModuleManagerDelegate
 import com.facebook.react.TurboReactPackage
+import com.facebook.react.ViewManagerOnDemandReactPackage
 import com.facebook.react.bridge.JSBundleLoader
 import com.facebook.react.bridge.NativeModule
 import com.facebook.react.bridge.ReactApplicationContext
@@ -108,7 +109,7 @@ class RNTesterReactHostDelegate internal constructor(context: Context) : ReactHo
                 }
               }
         },
-        object : ReactPackage {
+        object : ViewManagerOnDemandReactPackage, ReactPackage {
           override fun createNativeModules(
               reactContext: ReactApplicationContext
           ): List<NativeModule> = emptyList()
@@ -117,6 +118,22 @@ class RNTesterReactHostDelegate internal constructor(context: Context) : ReactHo
               reactContext: ReactApplicationContext
           ): List<ViewManager<*, *>> =
               listOf(MyNativeViewManager(), MyLegacyViewManager(reactContext))
+
+          override fun getViewManagerNames(
+              reactContext: ReactApplicationContext
+          ): Collection<String> =
+              listOf(MyNativeViewManager.REACT_CLASS, MyLegacyViewManager.REACT_CLASS)
+
+          override fun createViewManager(
+              reactContext: ReactApplicationContext,
+              viewManagerName: String
+          ): ViewManager<*, *>? {
+            return when (viewManagerName) {
+              MyNativeViewManager.REACT_CLASS -> MyNativeViewManager()
+              MyLegacyViewManager.REACT_CLASS -> MyLegacyViewManager(reactContext)
+              else -> null
+            }
+          }
         })
   }
 }

packages/rn-tester/android/app/src/main/java/com/facebook/react/uiapp/component/MyLegacyViewManager.kt

@@ -26,8 +26,8 @@ internal class MyLegacyViewManager(reactContext: ReactApplicationContext) :
 
   override fun getName(): String = REACT_CLASS
 
-  override fun createViewInstance(reactContext: ThemedReactContext): MyNativeView =
-      MyNativeView(reactContext).apply { setBackgroundColor(Color.RED) }
+  override fun createViewInstance(themedReactContext: ThemedReactContext): MyNativeView =
+      MyNativeView(themedReactContext).apply { setBackgroundColor(Color.RED) }
 
   @ReactProp(name = ViewProps.OPACITY, defaultFloat = 1f)
   override fun setOpacity(view: MyNativeView, opacity: Float) {

packages/rn-tester/android/app/src/main/java/com/facebook/react/uiapp/component/MyNativeView.kt

@@ -7,21 +7,22 @@
 
 package com.facebook.react.uiapp.component
 
-import android.content.Context
 import android.graphics.Color
 import android.graphics.drawable.GradientDrawable
 import android.view.View
 import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.ReactContext
 import com.facebook.react.bridge.WritableArray
 import com.facebook.react.bridge.WritableMap
+import com.facebook.react.uimanager.ThemedReactContext
 import com.facebook.react.uimanager.UIManagerHelper
 import com.facebook.react.uimanager.events.Event
 import com.facebook.react.uimanager.events.RCTEventEmitter
 
-class MyNativeView(context: Context) : View(context) {
+class MyNativeView(context: ThemedReactContext) : View(context) {
   private var currentColor = 0
   private var background: GradientDrawable = GradientDrawable()
+  private var reactContext: ReactContext = context.getReactApplicationContext()
 
   override fun setBackgroundColor(color: Int) {
     if (color != currentColor) {
@@ -51,7 +52,6 @@ class MyNativeView(context: Context) : View(context) {
     Color.colorToHSV(color, hsv)
     event.putMap("backgroundColor", backgroundColor)
 
-    val reactContext = context as ReactContext
     reactContext.getJSModule(RCTEventEmitter::class.java).receiveEvent(id, "onColorChanged", event)
   }