Add docker group

TEST=none
BUG=brillo:823

Change-Id: Idfe50169c3b91483d66779a0282ecdf3eb8b3460
Reviewed-on: https://chromium-review.googlesource.com/266760
Commit-Ready: Andrey Ulanov <andreyu@google.com>
Tested-by: Andrey Ulanov <andreyu@google.com>
Reviewed-by: Chris Masone <cmasone@chromium.org>
diff --git a/profiles/base/accounts/group/docker b/profiles/base/accounts/group/docker
new file mode 100644
index 0000000..7816a8b
--- /dev/null
+++ b/profiles/base/accounts/group/docker
@@ -0,0 +1,3 @@
+group:docker
+gid:412
+password:!