Uncaught SyntaxError: Failed to set the 'href' property on 'Location'

We have a webpage that does a redirect with js. It works fine on ios, but we are getting this error when trying it on android:

```
Uncaught SyntaxError: Failed to set the 'href' property on 'Location'
```

This is causing the flutterWebViewPlugin.onStateChanged.listen listener to stop firing.

The js line that does the redirect looks like this:

```
window.location = e.data.url + (e.data.url.indexOf('?') == -1 ? '?' : '&') + (params || {});
```

The location value is:
```
?notifyApp=success&SiteCode=SPA-SPA-006&TransactionId=73143e1d-e64b-44d1-9a6f-23d35a92618c&TransactionReference=044ZVxHUJ1vBfVGtf8B2opaqiuV8qu0d&Amount=25.00&Status=Complete&Optional1=&Optional2=&Optional3=&Optional4=&Optional5=&CurrencyCode=ZAR&IsTest=True&StatusMessage=Test%20transaction%20completed&Hash=19e304e53f23d5c6b4329af9757e4ede0457b5f573bd8a17bf01eeb01ef283fd1129dc670ec8508b17ac6f579f2fbde0311f0928a670c42c8a161a621d6d5640'
```

Start by reproducing the redirect in the Android WebView using the reported JavaScript assignment and query-string value, then inspect how flutterWebViewPlugin.onStateChanged.listen responds. Done means the redirect no longer raises the Location href SyntaxError on Android and the listener continues firing, while preserving the reported iOS behavior.

Written by the indexing model from the issue text.