Move 'host.env' file to '/etc/container-service'

This consolidates configuration specific to the CoreOS home-server
setup, and thus makes this easier to manage.

config/common/systemd/container-environment@.service

@@ -1,11 +1,11 @@
 [Unit]
 Description=Container environment for %I
-ConditionPathExists=/etc/container-service.env
+ConditionPathExists=/etc/container-service/host.env
 ConditionPathExists=/etc/container-service/%i/%i.env.template
 
 [Service]
 Type=oneshot
-EnvironmentFile=/etc/container-service.env
+EnvironmentFile=/etc/container-service/host.env
 ExecStart=/bin/sh -c 'envsubst < /etc/container-service/%i/%i.env.template > /etc/container-service/%i/%i.env'
 
 [Install]

host/lhr01nuc/spec.bu

@@ -34,7 +34,7 @@ storage:
       contents:
         inline: lhr01nuc
 
-    - path: /etc/container-service.env
+    - path: /etc/container-service/host.env
       mode: 0600
       contents:
         local: lhr01nuc.env.gpg

host/virtual/spec.bu

@@ -88,7 +88,7 @@ storage:
         inline: core-virtual
 
     # Load host-wide environment into default location.
-    - path: /etc/container-service.env
+    - path: /etc/container-service/host.env
       mode: 0600
       contents:
         local: virtual.env