Does PLA have Russian Kamaz/Ural trucks in service, it says on the PLA ground force equipment Wikipedia page?
Not sure if this is true.
From what I understand China has good connections with the Belarussian truck industry. Just look at the Chinese HQ-17A wheeled vehicle and compare it with MZKT-6922 from Belarus. Or look at the most modern TELs used in the Chinese DF-41. Compare this with the early DF-31 launchers which were basically civilian heavy truck designs, not high mobility multiple axle all terrain vehicles. Belarus also provides Russia with the MZKT-79221 TEL vehicles used in the Topol-M and Yars missiles. Russia's KAMAZ also has a TEL design for Yars but it seems it had issues during testing and AFAIK never entered service in the Russian Federation. Chinese TELs seem to be based on Belarus truck technology cloned by China.
Any weapons systems imported from Russia proper like the S-400 should use Belarussian or Russian trucks, but the Chinese clones use Chinese made trucks of course. Not imports.
Belarus seems to have provided China with technical assistance in developing some of their heavy trucks much like Ukraine provided assistance with the airframe design of the Y-20 and Russia with the airframe design of the Z-10.