78a1c3cb28
On Android, KeyPairGenerator.getInstance("Ed25519") could resolve to
AndroidKeyStoreKeyPairGeneratorSpi, which rejects NamedParameterSpec and
requires KeyGenParameterSpec, crashing group creation with
IllegalArgumentException. Explicitly select a non-AndroidKeyStore
provider (Conscrypt on Android, SunEC on JVM) for KeyPairGenerator,
KeyFactory, and Signature, and drop the unnecessary initialize() call
since Ed25519 is fully specified by its algorithm name.