I think I would also go this route. First I would try to make sure he can feel can confident, then I would try to understand what is the "lame" thing and try to find some "wow" alternative, so kid could respond with "does your phone can do that?"
I was also bullied as a kid and when my kid will have similar issue, I will try to explain him how bullying work and what gives then satisfaction, so he could stay confident and show something unique about himself.
As I think OP is technical person that knows well android ecosystem, maybe he could even build some cool app (something that just looks cool, depending what kid would think would impress other kids) - eg maybe some chat app that with gptchat with prompt to pretend to be some celebrity/YouTuber/etc?