How about you simply... provide them with a photo? Download a face here (https://thispersondoesnotexist.com/ https://thispersondoesnotexist.com/ - you may have

How about you simply... provide them with a photo? Download a face here (https://thispersondoesnotexist.com/ https://thispersondoesnotexist.com/ - you may have to reload a few times to get a suitable face), and send it to Google to use as your avatar. Maybe set up a website where you feature the same photo and promote the books. Doing ridiculous things is often the only way to deal with ridiculous problems. This seems to fit all your constraints (i.e. your face isn't visible online, and Google stops bothering innocent bystanders). That it isn't really you - who is to know? What is the harm?