Keystore: Validate curve names in XDH and ED25519

Added a ED25519 key pair generator algorithm in AndroidKeyStoreProvider.
This will allow user to generate ED25519 key pair using
KeyPairGenerator.

Key pair generator for algorithm XDH (Agree-Key) and ED25519
(Signing-Key) should only allow curve X25519 and curve Ed25519
respectively. This expectation is checked in
AndroidKeyStoreKeyPairGeneratorSpi.

Bug: 223547517
Test: atest CtsKeystoreTestCases:android.keystore.cts.Curve25519Test
Change-Id: Ib664637ffa90eec4fd4605007c53aca584eb3799