postMessage from HTML file to react-native results in app crash

`“react-native-wkwebview-reborn”: “1.22.0",`

```
{
this.webview = wbref;
}}
style={{ backgroundColor: 'red' }}
source={require('../../../../../../ios/3dView/car.html')}
onLoadStart={this.onLoadStart}
onLoad={this.onLoad}
onLoadEnd={this.onLoadEnd}
onError={this.onError}
renderError={this.renderError}
onMessage={this.handleMessageFromBuilder}
cacheEnabled={false}
cookiesEnabled={false}
scalesPageToFit
bounces={false}
scrollEnabled={false}
/>
```

When i postMessage from html file to react-native it crashes.
```
window.postMessage(JSON.stringify({
type: ‘READY_TO_RENDER’
}), ‘*’);
```

Additional info
```

Environment:
OS: macOS High Sierra 10.13.6
Node: 9.6.1
Yarn: Not Found
npm: 5.6.0
Watchman: 4.9.0
Xcode: Xcode 10.0 Build version 10A255
Android Studio: 3.1 AI-173.4819257

Packages: (wanted => installed)
react: v16.3.2 => 16.3.2
react-native: 0.53 => 0.53.3
```

Start with ios/3dView/car.html and the WKWebView usage shown in the issue, then trace the onMessage handler handleMessageFromBuilder. Reproduce the crash using the provided window.postMessage payload and inspect the native React Native WebView path; done means the message is delivered without crashing under the stated environment.

Written by the indexing model from the issue text.