Is there any generalized symbol for an electrolytic or electroplating cell?
There is no single generalized symbol, because the most well-known electrical symbols usually denote either basic components (transistors, electrolytic capacitors, etc.) or enclosed products (amplifiers, sources, outputs). Beyond the classics you see in circuit design programs, there is a wider class of sketch-like symbols that most will figure out, like the "winding on soft iron core", which could be included in diagrams, perhaps accompanied by "soft Fe".

The idea of an electrochemical cell is fundamental enough that the question is very reasonable. However, the fact the images you provided appear at the top of my image search results for electroplating cell electrical symbol suggests there is no firm shorthand for this. I would suggest the sort of diagram used for chemistry labs:



Replace "battery" with a DC cell symbol, drop the ammeter if unneeded, maybe add waves to the surface, and the concept will get across and take up no more space than the "electrical circuit" in the sample image.