Add KDoc documentation to ViewManagerOnDemandReactPackage (#54394)

Summary:
Pull Request resolved: #54394

Added comprehensive KDoc documentation to the ViewManagerOnDemandReactPackage interface and its public methods.

This interface enables lazy initialization of ViewManagers by deferring their creation until they are actually needed by JavaScript code. The documentation explains the purpose, benefits, and implementation considerations of this on-demand loading pattern.

The documentation includes:
- Interface-level overview explaining the lazy loading pattern and its performance benefits
- Detailed method documentation for getViewManagerNames() and createViewManager()
- Thread safety considerations
- Parameter and return value descriptions
- Usage guidelines and best practices

changelog: [internal] internal

Reviewed By: alanleedev

Differential Revision: D86012042

fbshipit-source-id: d54fef193111c76e07aab0b69f2b567d69856bf6

Author: mdvacca

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ViewManagerOnDemandReactPackage.kt

@@ -10,16 +10,65 @@ package com.facebook.react
 import com.facebook.react.bridge.ReactApplicationContext
 import com.facebook.react.uimanager.ViewManager
 
+/**
+ * Interface for React Native packages that provide ViewManagers on-demand rather than eagerly.
+ *
+ * This interface enables lazy initialization of ViewManagers, improving startup performance by
+ * deferring the creation of ViewManager instances until they are actually needed by the JavaScript
+ * code. Instead of instantiating all ViewManagers during package initialization, implementing
+ * classes can defer creation until a specific ViewManager is requested by name.
+ *
+ * This pattern is particularly beneficial for applications with many ViewManagers, as it reduces
+ * memory footprint and initialization time by only creating the ViewManagers that are actively
+ * used.
+ *
+ * Implementing classes should maintain a registry or factory mechanism to create ViewManagers based
+ * on their names when requested.
+ *
+ * @see com.facebook.react.uimanager.ViewManager
+ * @see com.facebook.react.ReactPackage
+ */
 public interface ViewManagerOnDemandReactPackage {
   /**
-   * Provides a list of names of ViewManagers with which these modules can be accessed from JS.
-   * Typically, this is ViewManager.getName().
+   * Provides the names of all ViewManagers available in this package.
+   *
+   * This method returns a collection of ViewManager names that can be accessed from JavaScript. The
+   * names returned should match the values returned by [ViewManager.getName] for each ViewManager
+   * that this package can create. The React Native framework uses these names to determine which
+   * ViewManagers are available and to request their creation on-demand.
+   *
+   * This method is called during the initialization phase to register available ViewManagers
+   * without actually instantiating them, enabling lazy loading.
+   *
+   * @param reactContext The React application context, which provides access to the Android
+   *   application context and React Native lifecycle information
+   * @return A collection of ViewManager names. Returns an empty collection if no ViewManagers are
+   *   available. The returned names should be unique within this package
    */
   public fun getViewManagerNames(reactContext: ReactApplicationContext): Collection<String>
 
   /**
-   * Creates and returns a ViewManager with a specific name {@param viewManagerName}. It's up to an
-   * implementing package how to interpret the name.
+   * Creates and returns a ViewManager instance for the specified name.
+   *
+   * This method is called lazily when a ViewManager is actually needed by the JavaScript code,
+   * rather than during package initialization. The implementation should create and configure the
+   * appropriate ViewManager based on the provided name. The name parameter corresponds to one of
+   * the names returned by [getViewManagerNames].
+   *
+   * Implementations have flexibility in how they interpret the name and create ViewManagers. For
+   * example, they might use a factory pattern, reflection, or a simple name-to-class mapping.
+   *
+   * This method may be called on any thread, so implementations should ensure thread safety if
+   * necessary.
+   *
+   * @param reactContext The React application context, which provides access to the Android
+   *   application context and React Native lifecycle information needed to initialize the
+   *   ViewManager
+   * @param viewManagerName The name of the ViewManager to create, matching one of the names
+   *   returned by [getViewManagerNames]
+   * @return A ViewManager instance for the specified name, or null if the name is not recognized or
+   *   the ViewManager cannot be created. Returning null will result in a JavaScript error when the
+   *   native component is used
    */
   public fun createViewManager(
       reactContext: ReactApplicationContext,