termina_build_image: create mount directories for lxd

Also copy in the about_os_credits.html for display by the host.

BUG=chromium:806119
TEST=./termina_build_image

Change-Id: I7d77650c8da37edebf362c5bef00a8f9d553a696
Reviewed-on: https://chromium-review.googlesource.com/894284
Commit-Ready: Stephen Barber <smbarber@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
diff --git a/termina_build_image b/termina_build_image
index 065d3ea..b5db258 100755
--- a/termina_build_image
+++ b/termina_build_image
@@ -108,8 +108,8 @@
   sudo rm -rf "${rootfs}/lib/firmware"
   # Get rid of stateful, it's not needed on termina.
   sudo rm -rf "${rootfs}/mnt/stateful_partition"
-  # Create container rootfs and private dirs.
-  sudo mkdir "${rootfs}"/mnt/{container_rootfs,container_private}
+  # Create container stateful and shared dirs.
+  sudo mkdir "${rootfs}"/mnt/{stateful,shared}
   # Copy the dev_image into its location at /usr/local.
   sudo cp -aT "${stateful}"/dev_image "${rootfs}/usr/local"
 
@@ -121,6 +121,8 @@
   sudo rm -rf "${rootfs}"/boot/vmlinuz*
 
   sudo cp "${rootfs}/etc/lsb-release" "${output_dir}/lsb-release"
+  sudo cp "${rootfs}/opt/google/chrome/resources/about_os_credits.html" \
+      "${output_dir}/about_os_credits.html"
 
   case "${fs_type}" in
   squashfs)