I don't know if the evidence is conclusive, but I do think we can say China is supplying Russia with military hardware and supporting them in other ways. So.. it's possible.
China is not allied with Russia and China is unlikely to engage in sabotage like this because they stand nothing to gain from it.
They don't have a mutual defense treaty, sure, but they describe themselves as having a “friendship without limits”. I would agree that China has no interest in getting involved in Putin's idiot war in Ukraine though, and there's zero benefit to China in antagonizing Europe.
What the words are worth in a time of need remains to be seen. Neither side is exactly trustworthy :)