Make AesByesEncryptor public

Fixes: gh-5099

crypto/src/main/java/org/springframework/security/crypto/encrypt/AesBytesEncryptor.java

@@ -41,7 +41,7 @@ import org.springframework.security.crypto.keygen.KeyGenerators;
  * @author Keith Donald
  * @author Dave Syer
  */
-final class AesBytesEncryptor implements BytesEncryptor {
+public final class AesBytesEncryptor implements BytesEncryptor {
 
 	private final SecretKey secretKey;