I doubt that anything was installed on your computer simply by declining to accept Google’s Terms and Conditions for Google Analytics. I also doubt declining the T&Cs has any connection to Google asking for your phone number. The phone number request is something everybody gets (me in included) every once in awhile. It’s Google’s way of making sure you don’t lose access to your account. If you forget your password, for example, I believe you can reset it by phone (an automated system will call you, or send you a text message, with a code to reset your password).
I hope this was helpful!