Stable API - Make InteropModuleRegistry internal

Summary:
I've converted this class to Kotlin + made it `internal` as it should not be exposed publicly.
This class is part of the iterop layer for the New Architecture.
Marked as breaking but I expect no meaningful breakages here.

Changelog:
[Android] [Breaking] - Stable API - Make InteropModuleRegistry internal

Differential Revision: D65421965

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -1644,13 +1644,6 @@ public final class com/facebook/react/bridge/WritableNativeMap : com/facebook/re
 	public fun putString (Ljava/lang/String;Ljava/lang/String;)V
 }
 
-public class com/facebook/react/bridge/interop/InteropModuleRegistry {
-	public fun <init> ()V
-	public fun getInteropModule (Ljava/lang/Class;)Lcom/facebook/react/bridge/JavaScriptModule;
-	public fun registerInteropModule (Ljava/lang/Class;Ljava/lang/Object;)V
-	public fun shouldReturnInteropModule (Ljava/lang/Class;)Z
-}
-
 public abstract interface class com/facebook/react/bridge/queue/MessageQueueThread {
 	public abstract fun assertIsOnThread ()V
 	public abstract fun assertIsOnThread (Ljava/lang/String;)V

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactContext.java

@@ -63,6 +63,8 @@ public interface RCTDeviceEventEmitter extends JavaScriptModule {
   private @Nullable JSExceptionHandler mExceptionHandlerWrapper;
   private @Nullable WeakReference<Activity> mCurrentActivity;
 
+  // NOTE: When converted to Kotlin, this field should be made internal due to
+  // visibility restriction on InteropModuleRegistry otherwise it will be exposed to the public API.
   protected @Nullable InteropModuleRegistry mInteropModuleRegistry;
   private boolean mIsInitialized = false;
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/interop/InteropModuleRegistry.kt

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+package com.facebook.react.bridge.interop
+
+import com.facebook.react.bridge.JavaScriptModule
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags.enableFabricRenderer
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags.useFabricInterop
+
+/**
+ * A utility class that takes care of returning [JavaScriptModule] which are used for the
+ * Fabric Interop Layer. This allows us to override the returned classes once the user is invoking
+ * `ReactContext.getJsModule()`.
+ *
+ * Currently we only support a `RCTEventEmitter` re-implementation, being `InteropEventEmitter`
+ * but this class can support other re-implementation in the future.
+ */
+internal class InteropModuleRegistry {
+  private val supportedModules = mutableMapOf<Class<*>, Any?>()
+
+  fun <T : JavaScriptModule?> shouldReturnInteropModule(requestedModule: Class<T>): Boolean {
+    return checkReactFeatureFlagsConditions() && supportedModules.containsKey(requestedModule)
+  }
+
+  fun <T : JavaScriptModule?> getInteropModule(requestedModule: Class<T>): T? {
+    return if (checkReactFeatureFlagsConditions()) {
+      @Suppress("UNCHECKED_CAST")
+      supportedModules[requestedModule] as? T?
+    } else {
+      null
+    }
+  }
+
+  fun <T : JavaScriptModule?> registerInteropModule(
+    interopModuleInterface: Class<T>, interopModule: Any
+  ) {
+    if (checkReactFeatureFlagsConditions()) {
+      supportedModules[interopModuleInterface] = interopModule
+    }
+  }
+
+  private fun checkReactFeatureFlagsConditions(): Boolean =
+    enableFabricRenderer() && useFabricInterop()
+}

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/bridge/interop/InteropModuleRegistryTest.kt

@@ -24,7 +24,7 @@ import org.junit.Test
 @OptIn(UnstableReactNativeAPI::class)
 class InteropModuleRegistryTest {
 
-  lateinit var underTest: InteropModuleRegistry
+  private lateinit var underTest: InteropModuleRegistry
 
   @Before
   fun setup() {