I bet they did according to Xi and the CCP, but not in reality.
Even if they did, they're probably faking it because trade with China is more important to them than human rights, just like the US and Saudi Arabia or the other Western countries and the US..
"aborigines" is not a great word to use these days. It's generally seen as pretty offensive to Indigenous Australians as it's a bit dehumanising and comes from colinisers who treated people like animals.
Better to go with "First Nations people", "Aboriginal and Torres Strait Islander people" or "Indigenous Australians."
But yes, they've been treated (and in many cases continue to be treated) pretty horribly.
Blaming the Catholic Church is a good way to start but the argument that Irish people were led astray by the Church is pretty much the same argument as those who seek to divorce the Wehrmacht from complicity in SS atrocities. In both cases the answer is that they shared vital infrastructure with each other and ranking officials could have stopped the excesses, which they had full knowledge of, if they'd have disagreed with it.