feat(app_check, mobile): add option to pass debugTokens in initialization

[xVemu]

Description

This feature allows a developer to use a pre-generated debug token instead of one that is generated at runtime. It's useful in CI environments, where you don't have an option to copy token from logs and paste it to Firebase Console.

Related Issues

Fix for: #11719

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[Lyokone]

Hello @xVemu, thanks for your PR, could you add some tests in the tests/integration_test/firebase_app_check

[xVemu]

@Lyokone something like this?

[Lyokone]

Thanks, I'll have a look at the API (we might want to have appleDebugToken instead of iosDebugToken). But otherwise it looks good :)

[Fudal]

@xVemu any update for that?

[xVemu]

@xVemu any update for that?

I guess we have to wait for Firebase team?