This change appends the full hostname to the mirror pod name (instead of taking
the first token) so that if the hostname is overriden, we'd not be creating
unncessary name conflicts. An example would be that a user overrides the
hostnames to be "127.0.0.1" and "127.0.0.2", and both of them were resolved to
"127" for the mirror pod name suffix.
Also, because `uname -n` could return a FQDN or not, this change takes only
the first token of it as the hostname for consistency.
Hostname behavior across operating systems is inconsistent (Macs can
have uppercase host names, so can some other systems). In general,
always strings.ToLower(os.Hostname()).
