It was present a month ago, but now all of a sudden it has disappeared.
My apache is running normally on a gcloud VM & it already had monitoring client installed because I was able to monitor the web server statistics. But now all of a sudden it has stopped showing up.
It seems that one needs to configure linkage between Apache and Cloud Monitoring. Since monitoring was previously present, I get the feel that this was done historically … but maybe somehow it got “lost”? Maybe someone re-installed Apache and the recipe needs redone?