Filter out puppetteers in services usage metrics

[elisabettai]

It would be nice to have a way to filter out dynamic and computational services starter by the puppeteer.

For now the only way is to subtract those values manually, as explained here.
Doing it manually gives a rough estimate and we need also to take into account when new e2e tests are introduced, which will probably become even more frequent with the upcoming product releases.

[sanderegg]

@GitHK there was an entry where you added the user agent. How can I see that entry in prometheus ? (also @mrnicegyu11 shall know that and could add a link to prometheus where we see this?). looking at container metrics I do not see it in master.

Now next question is:
if I look in prometheus at this entry for example I do not see the user agent. and we should add that as well.