When using iosCustomBrowser after a redirect it does not return authorization tokens

## Issue

If I remove iosCustomBrowser from the config file, authorization occurs within the app in a drop-down WebView. But this option doesn't suit me. I want to use the login and password saving feature provided by iosCustomBrowser: 'safari'. When the user is redirected to a separate browser window, after successful authorization, I'm returned to the app, and the result doesn't produce any logs or anything. In the inspector, I don't see a URL that ends in protocol/openid-connect/token with the POST method. As soon as I remove iosCustomBrowser: 'safari', everything starts working again. I'm looking for a way to save the login and password. If you have an alternative solution, I'd be glad to see it. Thanks.

---

## Environment

I updated react-native-app-auth to version 8.1.0

I'm using the following config

const config: AuthConfiguration = {
iosCustomBrowser: 'safari',
iosPrefersEphemeralSession: true,
redirectUrl: redirectUrl,
androidAllowCustomBrowsers: ['chrome'],
additionalParameters: {
prompt: 'login',
},
androidTrustedWebActivity: true,
clientId: clientId,
issuer: issuerUri,
scopes: ['openid', 'profile'],
usePKCE: true,
skipCodeExchange: false,
};

I'm using the authorization method
const result = await authorize(config);

Keycloak type auth

IOS device

"react-native-app-auth": "8.1.0",
"react-native": "0.76.0",

I'm not used expo

Inizia con authorize(config) usando la configurazione fornita di react-native-app-auth 8.1.0 e riproduci il flusso iOS con iosCustomBrowser impostato su safari e la redirectUrl indicata. Confrontalo con il flusso funzionante del browser in-app; è completato quando un reindirizzamento Safari riuscito restituisce token di autorizzazione e avviene lo scambio dei token.

Scritto dal modello di indicizzazione a partire dal testo della issue.