That's the application software side. I would assume the IMEI and IMSI are both going out to the cell network though, and I would presume that it's trivial to tie a phone number to those with how the mobile industry generally sells subscriber data to various data brokers. The only question is how permissive those data brokers are (their major constraint is how much most people become aware of this dynamic), but when dealing with a major APT like Google I'd assume they're tuned into the best ones with songs about bona fide purposes.