In Australia, you can't legally record phone calls without others permission. If you insisted on doing so, you're required by law to state that you are recording the call. Otherwise, the recordings won't be accepted in legal matters. This is likely why Samsung, Google and others don't offer it on their Australian models, as it could cause them too many headaches.
Having said that, there are some apps on the Play Store that claim to be able to do call recording, but I have no experience with them, so I can not recommend any.
