Is it referred to African blacks, or for aboriginals as well?
The people who use it use it to refer to anybody who is black. Historically it was mostly used for indigenous Australians because they were the largest black group around - there weren’t all that many African immigrants until Australia until recently, but I’m sure they cop the phrase.
Most Australians aren’t racist - but unfortunately we do have some who are. And I’ll happily condemn anybody who does use a slur against another - but I don’t think it does anybody any good to focus on things like the name of a cheese. That effort would be better off directed at the actual bigots who are still around.
I don’t even oppose changing some names where the names genuinely are racist on some level - but things like this just make that look stupid.