>>...Canon, a Japanese company, stopped all exports of its products to Russia

DJI drones are made in China. Their cameras are available separately and are good - as are their gimbals (photographer here). Also, there are action cams (many 4K / 30FPS) made in China. For that matter GoPro cameras are made in China, Mexico, and Thailand - and factories in China often make more of whatever-it-is, and sell them directly (via places like Aliibaba).

I'd expect an issue in modifying whatever interface electronics they currently have to connect Canon cameras to whatever radio system they're using to suit whatever they might have available from China. Many action cameras can connect via Wifi, but that's easily detected / disrupted. I'd guess it's a matter of producing a custom ASIC or programming an Arduino - which they may or may not have the capacity to do (IMO Arduinos are pretty easy).