When using the add_host_metadata Metricbeat processor it would be useful to include the Operating System name so it returns the following field value in Windows

Microsoft Windows Server 2012 R2 Datacenter

Might also be worthy to add the same for other Operating Systems that Metricbeat supports so that you'd have fields similar to

Ubuntu 18.04 LTS
CentOS Linux 7
Red Hat Enterprise Linux Server 7.3