Add <displayname>.<domain> to each sudoer host.

This is a bit of a hack to support backwards-compatibility.

Old (pre-essex) instances indentify themselves with a fqdn
like i-xxxxxxx.<domain>.  Newer instances identify themselves
as <displayname>.<domain>.  Previously our sudoer code
only registered i-xxxxx names, so per-host sudo policies
only worked for those older instances.

Now we just register both kinds of fqdn as part of a sudoer,
in order to support both old and new instances.  The GUI
consolidates both entries into one checkbox that looks
the same as before.

Change-Id: I46a63611d0fc731b0fb6bc82aadda48134ec08f1
Merge "Add <displayname>.<domain> to each sudoer host."