add code like this maybe better

[mmorcc]

package com.akulyk.react.androidwebview;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.graphics.Color;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.widget.FrameLayout;

import static android.view.ViewGroup.LayoutParams;

/**

• Provides support for full-screen video on Android
  */
  public class VideoEnabledWebChromeClient extends WebChromeClient {

  private final FrameLayout.LayoutParams FULLSCREEN_LAYOUT_PARAMS = new FrameLayout.LayoutParams(
  LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, Gravity.CENTER);

  private WebChromeClient.CustomViewCallback mCustomViewCallback;

  private Activity mActivity;
  private View mWebView;
  private View mVideoView;

  public VideoEnabledWebChromeClient(Activity activity, WebView webView) {
  mWebView = webView;
  mActivity = activity;
  }

  @OverRide
  public void onShowCustomView(View view, CustomViewCallback callback) {
  if (mVideoView != null) {
  callback.onCustomViewHidden();
  return;
  }

   // Store the view and it's callback for later, so we can dispose of them correctly
   mVideoView = view;
   mCustomViewCallback = callback;
  
   view.setBackgroundColor(Color.BLACK);
  
   getRootView().addView(view, FULLSCREEN_LAYOUT_PARAMS);
  
   mWebView.setVisibility(View.GONE);
   if(mActivity!=null){
       mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
       WindowManager.LayoutParams params = mActivity.getWindow().getAttributes();
       params.flags |= WindowManager.LayoutParams.FLAG_FULLSCREEN;
       mActivity.  getWindow().setAttributes(params);
       mActivity.  getWindow().addFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);
   }
  

  }

  @OverRide
  public void onHideCustomView() {
  if (mVideoView == null) {
  return;
  }

   mVideoView.setVisibility(View.GONE);
  
   // Remove the custom view from its container.
   getRootView().removeView(mVideoView);
   mVideoView = null;
   mCustomViewCallback.onCustomViewHidden();
  
   mWebView.setVisibility(View.VISIBLE);
   if(mActivity!=null){
       mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
       final WindowManager.LayoutParams attrs =mActivity.getWindow().getAttributes();
       attrs.flags &= (~WindowManager.LayoutParams.FLAG_FULLSCREEN);
       mActivity.getWindow().setAttributes(attrs);
       mActivity.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);
   }
  

  }

  private ViewGroup getRootView() {
  return ((ViewGroup) mActivity.findViewById(android.R.id.content));
  }
  }

[mmorcc]

add code in mainfest.xml
application
android:hardwareAccelerated="true"
or else it don't work properly