To share several files and folder from GCP to a dynamic https endpoint is very easy on cloud shell.
We just have to type :
For python 2.7
python2.7 -m SimpleHTTPServer 8080
For python 3+
python3.7 -m http.server 8080
Then, clicking on the web preview, it will create dynamically an https 443 to 8080 ReverseProxy hosted on appspot.