AS15169 is one of the largest networks on the internet by traffic. Google Cloud customer VMs typically appear under AS396982 (Google Cloud) rather than AS15169, so an address in AS15169 is usually Google's own infrastructure — crawlers (Googlebot), DNS, or front-end servers.
For fraud and bot detection, AS15169 traffic is mostly automated: Googlebot, Google Ads verification, Google Cloud NAT egress. Verify Googlebot by reverse DNS (hostnames end in googlebot.com or google.com) rather than by ASN alone.