package com.allaboutolaf;

import android.os.Bundle;

import com.facebook.react.ReactActivity;
import com.facebook.react.ReactActivityDelegate;
import com.facebook.react.ReactRootView;
import com.facebook.react.modules.storage.ReactDatabaseSupplier;

public class MainActivity extends ReactActivity {

    /**
     * Returns the name of the main component registered from JavaScript.
     * This is used to schedule rendering of the component.
     */
    @Override
    protected String getMainComponentName() {
        return "AllAboutOlaf";
    }

    /**
     * Returns the instance of the {@link ReactActivityDelegate}. There the RootView is created and
     * you can specify the renderer you wish to use (Fabric or the older renderer).
     */
    @Override
    protected ReactActivityDelegate createReactActivityDelegate() {
        return new ReactActivityDelegate(this, getMainComponentName());
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        long size = 50L * 1024L * 1024L; // 50 MB
        ReactDatabaseSupplier.getInstance(getApplicationContext()).setMaximumSize(size);
    }

    public static class MainActivityDelegate extends ReactActivityDelegate {
        public MainActivityDelegate(ReactActivity activity, String mainComponentName) {
            super(activity, mainComponentName);
        }
        @Override
        protected ReactRootView createRootView() {
            ReactRootView reactRootView = new ReactRootView(getContext());
            // If you opted-in for the New Architecture, we enable the Fabric Renderer.
            reactRootView.setIsFabric(BuildConfig.IS_NEW_ARCHITECTURE_ENABLED);
            return new reactRootView;
        }
    }
}

package com.allaboutolaf;

import android.os.Bundle;

import com.facebook.react.ReactActivity;
import com.facebook.react.ReactActivityDelegate;
import com.facebook.react.ReactRootView;
import com.facebook.react.modules.storage.ReactDatabaseSupplier;

public class MainActivity extends ReactActivity {

    /**
     * Returns the name of the main component registered from JavaScript.
     * This is used to schedule rendering of the component.
     */
    @Override
    protected String getMainComponentName() {
        return "AllAboutOlaf";
    }

    /**
     * Returns the instance of the {@link ReactActivityDelegate}. There the RootView is created and
     * you can specify the renderer you wish to use (Fabric or the older renderer).
     */
    @Override
    protected ReactActivityDelegate createReactActivityDelegate() {
        return new MainActivityDelegate(this, getMainComponentName());
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        long size = 50L * 1024L * 1024L; // 50 MB
        ReactDatabaseSupplier.getInstance(getApplicationContext()).setMaximumSize(size);
    }

    public static class MainActivityDelegate extends ReactActivityDelegate {
        public MainActivityDelegate(ReactActivity activity, String mainComponentName) {
            super(activity, mainComponentName);
        }
        
        @Override
        protected ReactRootView createRootView() {
            ReactRootView reactRootView = new ReactRootView(getContext());
            // If you opted-in for the New Architecture, we enable the Fabric Renderer.
            reactRootView.setIsFabric(BuildConfig.IS_NEW_ARCHITECTURE_ENABLED);
            return reactRootView;
        }
    }
}

use MainActivityDelegate in createReactActivityDelegate