Allow administrators to disable first run experience in enterprise environments

It would be very helpful if we could disable the first run experience in enterprise environments.
Since we are deploying the addon automatically, the “Bitwarden Getting Started” page suddenly being opened is very confusing to our users.

The easiest way to implement this would be to use the cross-browser/os mechanism, same as for the centrally managed self-host url (see browser-environment.service.ts).

This can then be used in on-install-listener.ts to conditionally open the page.