Improve error message when long password is used for config encryption on machine without JCE policies

If the user runs ./bin/encrypt-config.sh with a password longer than 16 bytes on a machine without the JCE unlimited strength cryptographic jurisdiction policies installed, an Illegal Key Size exception will be thrown and the full stack trace will be printed (in verbose mode).

We should detect the absence/presence of strong crypto availability and perform a length check on the password before attempting to derive the encryption key from this value in order to provide better error messaging.