I know you can use Bixby Routines to set up a bit of a custom charging animation, but are you asking if you can set up a persistent one? That I'm not sure about. Have to check.
Doing a little digging, looks like the option for a persistent animation would require downloading an app off the store. It's a neat idea but I would be wary of what permissions the apps ask for and personally, I don't need the phone lit up while it's charging, especially if I'm trying to sleep or if it slows the actual charging time. Different strokes for different folks 😁
