Unfortunately, I was not surprised. I put forth the thought some months or more back in a post around here that I thought Google was going to buy this company. That was before the opt-out feature started for Google Drive. I think there is a third Google service/tool also offered in an opt-out manner when people use an Avast product. Of course, Chrome was the first.
But you are right that it is rather disturbing for some people to think of Google having so much control over this company now that their own documents such as that “Google Policies and Principles” are now what we are shown when we click on “Privacy and Terms” on an Avast support page.
And please let it be noted that I wrote “for some people”.