SEC-2259: make bit strength configurable in AesBytesEncryptor

[spring-projects-issues]

Federico Schroder (Migrated from SEC-2259) said:

AesBytesEncryptor defaults to 256 bit, which doesn't work by default in a regular jvm (it needs Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files). It would be nice if this worked out of the box and/or the class javadocs mentioned it.