do not require unrestricted key with oauth flows

### Description

As per [this issue](https://github.com/firebase/firebase-ios-sdk/issues/11287) an api key must be unrestricted in order to use phone authentication on a simulator. Unrestricted in this scenario means that the api key must be allowed on any platform to not encounter an error of the sort: `Requests from this iOS client application are blocked.`.

**Firebase ios sdk should allow another api key to be used by the recaptcha flow, which is its intended use case.** This would allow to restrict the ios api key for ios only and use another key for the web flows.

Related:

- https://github.com/firebase/firebase-ios-sdk/issues/11287
- https://github.com/firebase/firebase-ios-sdk/issues/7653

### Reproducing the issue

Restricting firebase API key on the google cloud console for the app's bundle identifier and try an oauth flow

### Firebase SDK Version

10.9

### Xcode Version

14.3

### Installation Method

CocoaPods

### Firebase Product(s)

Authentication

### Targeted Platforms

iOS

### Relevant Log Output

_No response_

### If using Swift Package Manager, the project's Package.resolved

_No response_

### If using CocoaPods, the project's Podfile.lock

_No response_

Start by reproducing an OAuth flow on iOS with an API key restricted to the app's bundle identifier, then compare it with the reCAPTCHA flow described in the issue. Done means the iOS key can remain iOS-restricted while a separate key is accepted for the reCAPTCHA/web flow without the blocked-client error.

Written by the indexing model from the issue text.