Your friend is lying and doesn’t know what he’s talking about, this little thing about having GPS in cell phones for emergency calls was a good idea back about 3 years ago, until people raged against it as seeing it as the government could spy on people seeing EXACTLY where they are.
as robmandu has stated, they use triangulation, it is far faster and much easier.
Honestly, don’t expect discreet GPS systems to be in phones, and/when they do and if/when someone finds, not very many people will be happy.
This wasn’t an issue back in the day because landlines are connected to a person’s address, when cell phones became less of a commodity and actually used by a number of people, they couldn’t be traced to their location, so police and rescue people etc. had to have a system to locate and help you. Triangulation is the simplest and best way to do it. GPS is far harder because it requires space, a fair amount of money, a sky (you can’t be found indoors with any GPS device).