Is “*.googleusercontent.com” used for internal services?

I am a bug bounty hunter. While searching for vulnerabilities in a private program, I saw a functionality that allows me to enter any code I want and it will execute them. Then I was thinking about SSRF, so I fill the code console with:

<iframe src="https://mywebsite.pw"></iframe> 

And then I got a HTTP request to my website mywebsite.pw:

GET / HTTP/1.1 Host: mywebsite.pw Connection: keep-alive Pragma: no-cache Cache-Control: no-cache Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/77.0.3835.0 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3 Accept-Encoding: gzip, deflate 

So I look at the IP address and then do nslookup, dig with this result:

$   nslookup xx.xx.xx.xxx xxx.xx.xx.xx.in-addr.arpa       name = xxx.xx.xx.xx.bc.googleusercontent.com.  Authoritative answers can be found from: xx.xx.in-addr.arpa      nameserver = ns-gce-public4.googledomains.com. xx.xx.in-addr.arpa      nameserver = ns-gce-public1.googledomains.com. xx.xx.in-addr.arpa      nameserver = ns-gce-public3.googledomains.com. xx.xx.in-addr.arpa      nameserver = ns-gce-public2.googledomains.com. ns-gce-public4.googledomains.com        internet address = xxx.xxx.xx.xxx ns-gce-public2.googledomains.com        internet address = xxx.xxx.xx.xxx ns-gce-public3.googledomains.com        internet address = xxx.xxx.xx.xxx ns-gce-public1.googledomains.com        internet address = xxx.xxx.xx.xxx ns-gce-public4.googledomains.com        has AAAA address xxxx:xxxx:xxxx:xx::xx ns-gce-public2.googledomains.com        has AAAA address xxxx:xxxx:xxxx:xx::xx ns-gce-public3.googledomains.com        has AAAA address xxxx:xxxx:xxxx:xx::xx ns-gce-public1.googledomains.com        has AAAA address xxxx:xxxx:xxxx:xx::xx  $   dig xx.xx.xx.xxx ; <<>> DiG 9.11.14-3-Debian <<>> xx.xx.xx.xxx ... ;; QUESTION SECTION: ;xx.xx.xx.xxx.                  IN      A  ;; ANSWER SECTION: xx.xx.xx.xxx.           0       IN      A       xx.xx.xx.xxx  ;; Query time: 20 msec ...  $   

(I have replaced some sensitive IP information to x)

And like you see, the IP address resolved to .bc.googleusercontent.com which means I don’t know is there any impact on this. Is .bc.googleusercontent.com a public service by Google that can’t make any connection with the internal server? Or .bc.googleusercontent.com is an internal cloud service that can even access metadata.google.internal?

Thank you.