Is it possible for google or apple to geoblock phones based on location? Limit function and services if they are in Russia, or Russian occupied Ukraine.
No. Android is open source, every phone maker can see what the OS is doing. Phone makers will take the source code, add something and remove something before compiling and packaging to ROM in the phone. If there is any dirty trick in the basic phone software, it is the phone maker not Google/Alphabet.
However, most android phones have Google service (SW) included. Google can block service to phones in a geographical area. The phone will still work except any google related service. There are lots of services and softwares that provide alternatives to google service.
One thing that google can really give headache is any software downloaded and purchased from google play store will cease to be upgradable, and once removed can not be reinstalled because google store is not accessible anymore.
