Update Docker image to use mount image not do mount itself

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

examples/docker.yml

@@ -2,7 +2,7 @@ kernel:
   image: "mobylinux/kernel:4.9.x"
   cmdline: "console=ttyS0 console=tty0 page_poison=1"
 init:
-  - mobylinux/init:c394f4bf59566206e5036798c058a9894a7e0fc8
+  - mobylinux/init:b2590ccfe6550c0ae1cd9a931f755c4e49074f8a
   - mobylinux/runc:b0fb122e10dbb7e4e45115177a61a3f8d68c19a9
   - mobylinux/containerd:c7f6ecdcbcb615a53edee556ba03c7c873bc8488
   - mobylinux/ca-certificates:eabc5a6e59f05aa91529d80e9a595b85b046f935
@@ -27,6 +27,15 @@ onboot:
     capabilities:
      - CAP_SYS_ADMIN
      - CAP_MKNOD
+  - name: mount
+    image: "mobylinux/mount:d2669e7c8ddda99fa0618a414d44261eba6e299a"
+    binds:
+     - /dev:/dev
+     - /var:/var:rshared,rbind
+    capabilities:
+     - CAP_SYS_ADMIN
+    rootfsPropagation: shared
+    command: ["/mount.sh", "/var/lib/docker"]
 services:
   - name: rngd
     image: "mobylinux/rngd:3dad6dd43270fa632ac031e99d1947f20b22eec9@sha256:1c93c1db7196f6f71f8e300bc1d15f0376dd18e8891c8789d77c8ff19f3a9a92"
@@ -46,7 +55,7 @@ services:
     net: host
     oomScoreAdj: -800
   - name: docker
-    image: "mobylinux/docker-ce:f6505961df89ca6b5d024f1ac5a6b986359786d1"
+    image: "mobylinux/docker-ce:741bf21513328f674e0cdcaa55492b0b75974e08"
     capabilities:
      - all
     net: host
@@ -54,7 +63,7 @@ services:
      - type: cgroup
        options: ["rw","nosuid","noexec","nodev","relatime"]
     binds:
-     - /dev:/dev
+     - /var/lib/docker:/var/lib/docker
      - /lib/modules:/lib/modules
 trust:
   image: