fix: add host template for AOSC (#5557)

templates/hosts.aosc.tmpl

@@ -0,0 +1,23 @@
+## template:jinja
+{#
+This file (/etc/cloud/templates/hosts.aosc.tmpl) is only utilized
+if enabled in cloud-config.  Specifically, in order to enable it
+you need to add the following to config:
+   manage_etc_hosts: True
+-#}
+# Your system has configured 'manage_etc_hosts' as True.
+# As a result, if you wish for changes to this file to persist
+# then you will need to either
+# a.) make changes to the master file in /etc/cloud/templates/hosts.aosc.tmpl
+# b.) change or remove the value of 'manage_etc_hosts' in
+#     /etc/cloud/cloud.cfg or cloud-config from user-data
+#
+#<ip-address>   <hostname.domain.org>   <hostname>
+{# The value '{{hostname}}' will be replaced with the local-hostname -#}
+127.0.0.1       {{fqdn}} {{hostname}}
+127.0.0.1       localhost
+
+# The following lines are desirable for IPv6 capable hosts
+::1             localhost ip6-localhost ip6-loopback
+ff02::1         ip6-allnodes
+ff02::2         ip6-allrouters