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.

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## 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

提供された react-native-app-auth 8.1.0 の設定を使用して authorize(config) から始め、iosCustomBrowser を safari に設定し、記載された redirectUrl を使用して iOS フローを再現します。動作しているアプリ内ブラウザフローと比較します。完了条件は、Safari によるリダイレクトが成功して認証トークンを返し、トークン交換が行われることです。

索引モデルが issue の本文から書いたものです。