Firebase Auth Emulator interferes with Firebase Storage

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### [REQUIRED] Step 2: Describe your environment

* Operating System version: Windows 11
* Firebase SDK version: ____
* Library version: 9.1.1
* Firebase Product: auth, storage

### [REQUIRED] Step 3: Describe the problem

We access the Auth and Storage services in our project using this Java Admin SDK.
Recently, we wanted to make use of the Auth Emulator for development purposes. However, after enabling the emulator by setting the `FIREBASE_AUTH_EMULATOR_HOST` environment variable, the Storage calls stop working and return 401 Unauthorized.

It seems that by setting the `FIREBASE_AUTH_EMULATOR_HOST` environment variable, the [whole project enters an emulator mode](https://github.com/firebase/firebase-admin-java/blob/e8ec68c97929972acdbe05b79b5ea18f077a08a2/src/main/java/com/google/firebase/auth/internal/Utils.java#L27) and [uses emulator credentials](https://github.com/firebase/firebase-admin-java/blob/master/src/main/java/com/google/firebase/ImplFirebaseTrampolines.java#L47). The emulator credentials should be made to only apply to Auth calls.

Furthermore, I could not even find a way to create two instances of FirebaseApps (one with the emulator enabled and one disabled), since the check for `FIREBASE_AUTH_EMULATOR_HOST` is static and shared program-wide.

#### Steps to reproduce:

Use Auth and Storage in a production project. Enable `FIREBASE_AUTH_EMULATOR_HOST` and Storage stops working.

Empieza leyendo src/main/java/com/google/firebase/auth/internal/Utils.java y src/main/java/com/google/firebase/ImplFirebaseTrampolines.java, especialmente el manejo de FIREBASE_AUTH_EMULATOR_HOST y de las credenciales del emulador. Reproduce el problema con Auth y Storage habilitados conjuntamente y, después, verifica que las llamadas a Storage sigan estando autorizadas mientras las credenciales del emulador se apliquen únicamente a Auth; comprueba también si distintas instancias de FirebaseApp pueden diferir en su configuración del emulador.

Escrito por el modelo de indexación a partir del texto del issue.