When no account is active, ensure that the root level route is always choose-account page

[PIG208]

This can happen if the account is logged out on a non-AccountRoute route. Normally this would be a page reachable from logged in account, such as "About Zulip" page.

When that happens, routes to be removed on logged out are removed, leaving only the "About Zulip" page on the navigator stack. Since the navigator stack is non-empty, the choose-account page route is not pushed onto the stack. The symptom is that the user can no longer log into another account.

Assigned a higher priority because this bug is relatively easy to reproduce:

• From the home page, navigate to "About Zulip" through the main-menu bottom sheet
• Invalidate the account's API key on web

Related:

• Handle invalid API key on register-queue #737
• store: Handle invalid API key on register-queue #1183

[gnprice]

Thanks. Can you spell out a specific repro recipe? It sounds like you have one but I'm not quite picking out what it is.

[gnprice]

I see, it looks like you've edited the description to add a repro recipe, thanks.

That recipe makes it straightforward to repro when one is trying, but I think this is a scenario that's going to be quite uncommon in practice. So I don't think this needs to be something that holds up the launch.