While Beijing and Moscow both take a hard stance against perceived foreign interference into their own internal affairs, it does not necessarily mean that each state will publicly defend the other's treatment of minorities or policies toward disputed territories. Russia is an increasingly revisionist power, while China tends to seek a stable world order without expansionism beyond China, except for Taiwan
As trading partners they seem to have a new shared agreement, on how to be a world influence and they are ideologically miles apart as is seen in Chinas policies in Africa and South America.
Russia will be able to still trade with china and many others so sanctions will not affect them, but China will stay out of this beyond that, as they gain nothing from getting involved.