Google-Certificates-Bridge User Agent .well-known/acme-challenge Requests

I recently have been having many requests coming from Google IPv4 and IPv6 addresses with the user agent “Google-Certificates-Bridge” accessing unique files within /.well-known/acme-challenge/XXXX.
A snippet from my Apache Log
64.233.172.141 - - [25/Dec/2018:23:30:30 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
64.233.172.145 - - [25/Dec/2018:23:30:40 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
64.233.172.143 - - [25/Dec/2018:23:30:50 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
64.233.172.146 - - [25/Dec/2018:23:31:00 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
2001:4860:4801:400a::35 - - [25/Dec/2018:23:31:10 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
64.233.172.144 - - [25/Dec/2018:23:31:20 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
2001:4860:4801:400a::19 - - [25/Dec/2018:23:31:30 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
66.102.8.40 - - [25/Dec/2018:23:31:39 +0000] "GET /.well-known/acme-challenge/XXXXXXXXXXXXX-XXXXXXXXXXXXX HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"
64.233.172.143 - - [25/Dec/2018:23:31:40 +0000] "GET /.well-known/acme-challenge/LjaR-XXXXXXXXXXXXX-lgf6-QW8 HTTP/1.1" 404 - "-" "Google-Certificates-Bridge"

These requests are used by Cpanel, Google and some other services for the purpose of verifying SSL certificates issued to the domain. No need to worry, as long as the requests are coming from a familiar IP, this is not likely attack traffic.