[Authflow] Investigate whether webpage in webview will reload

> not sure if only happen to me, the webpage open in Authgear Demo app will auto refresh if I open other app and back, so if user want to use other app to get TOTP code, need store page info and let it keep in same page after refresh.

Start by reproducing the Authgear Demo app behavior: open a webpage in the webview, switch to another app to obtain a TOTP code, and return. Inspect the webview lifecycle to determine whether the page reloads; done means the reload behavior and the required page-state preservation are confirmed.

Written by the indexing model from the issue text.