Is your feature request related to a problem? Please describe.
Argon2 Hashing algorithm is now supported by GCIP/Firebase Auth BE (Public docs). This should be supported in the Admin SDKs too.

Describe the solution you'd like
Add Argon2 Hash class along with other existing supported hash algorithms like Scrypt/Hmac,etc.

Describe alternatives you've considered
N/A

Additional context
API Proposal (Internal): go/firebase-auth-argon2-admin