Import patches-unapplied version 2.478 to ubuntu/artful-proposed

Imported using git-ubuntu import.

Changelog parent: ed2c2791c8

New changelog entries:
  [ Michael Hudson-Doyle ]
  * Two last minute server-live fixes:
    - Seed the subiquity snap to track the stable channel (LP: #1724410)
    - Remove snap.subiquity.started from subiquity's After=/Requires= as it
      does not fix the race condition they were intended to address and causes
      subiquity to be killed when snapd refreshes subiquity (LP: #1724411)

debian/changelog

@@ -1,3 +1,14 @@
+livecd-rootfs (2.478) artful; urgency=medium
+
+  [ Michael Hudson-Doyle ]
+  * Two last minute server-live fixes:
+    - Seed the subiquity snap to track the stable channel (LP: #1724410)
+    - Remove snap.subiquity.started from subiquity's After=/Requires= as it
+      does not fix the race condition they were intended to address and causes
+      subiquity to be killed when snapd refreshes subiquity (LP: #1724411)
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Tue, 17 Oct 2017 22:08:38 -0700
+
 livecd-rootfs (2.477) artful; urgency=medium
 
   * Fix server live image to pull subiquity from the stable channel, not

live-build/ubuntu-server/hooks/032-installer-squashfs.binary

@@ -64,7 +64,7 @@ snaps:
    channel: stable
    file: ${CORE_SNAP}
  - name: subiquity
-   channel: edge
+   channel: stable
    classic: true
    file: ${SUBIQUITY_SNAP}
 EOF

live-build/ubuntu-server/includes.binary/overlay/lib/systemd/system/subiquity.service

@@ -1,8 +1,8 @@
 [Unit]
 Description=Subiquity, the installer for Ubuntu Server
 After=systemd-user-sessions.service plymouth-quit-wait.service
-After=rc-local.service snap.subiquity.started.service
-Requires=snapd.service snap.subiquity.started.service
+After=rc-local.service
+Requires=snapd.service
 IgnoreOnIsolate=yes
 ConditionPathExists=/dev/tty0
 ConditionPathExists=!/run/subiquity/complete