Android phones, and possibly iPhones as well, have multiple options for screen locks, one of which is a pin. That said, it will block pin entry after a set amount of failures after which you have to wait a set amount of time or log in with your Google account. I imagine the wait time scales if you continue guessing, rendering this bot quite useless.
Yes, it's talking about the Android lockscreen pin.
But in the phone’s lockscreen, you are usually not bound by the 4-digit requirement of SIM card PINs, hence can use an arbitrary alphanumeric password (though likely rather short, as you have to enter it often on a small keyboard). 36^5 >> 10^4.
For that matter, 36^3 > 10^4, by about a factor of 5.