"jni": Update w.r.t. CL 16799

See: https://vanadium-review.googlesource.com/#/c/16799/

MultiPart: 3/4

Change-Id: I456e61e42e913e93f30593010bba41c37786a557
diff --git a/v23/security/jni.go b/v23/security/jni.go
index 5f4b630..bafd75b 100644
--- a/v23/security/jni.go
+++ b/v23/security/jni.go
@@ -322,7 +322,7 @@
 	}
 	// TODO(ataly): Implement BlessingsBasedEncrypter and BlessingsBasedDecrypter types
 	// in Java.
-	principal, err := security.CreatePrincipal(signer, store, roots, nil, nil)
+	principal, err := security.CreatePrincipal(signer, store, roots)
 	if err != nil {
 		jutil.JThrowV(env, err)
 		return nil
diff --git a/v23/security/principal.go b/v23/security/principal.go
index af5e0bd..626c53b 100644
--- a/v23/security/principal.go
+++ b/v23/security/principal.go
@@ -168,11 +168,3 @@
 	}
 	return roots
 }
-
-func (p *principal) Encrypter() security.BlessingsBasedEncrypter {
-	return nil
-}
-
-func (p *principal) Decrypter() security.BlessingsBasedDecrypter {
-	return nil
-}