Does it run applications? The point of the law is to collect (and device setup) the age of the (I guess primary?) user, and communicate that (as a range?) to any applications it runs. So, if you don't run applications, does this matter? Also, enforcement is by the CA attorney general, so random people can't go after you.
There's no further elaboration on what age signals are preferred, so my assumption is that a DoB field in the user profile and a system service to request the age bucket is good enough. It's absolutely silly, but DB48X could implement that.
There's a related question of who is actually liable under this law - it seems written to target just Apple, Google, and Microsoft; and it only makes sense in the context of consumer electronics. Like, how does this work with enterprise systems? Servers? Is IBM going to have to rush out a patch for z/VM to ask the system administrator what their date of birth is?