Likely caused by https://chromium-review.googlesource.com/c/aosp/platform/system/connectivity/shill/+/1132174. We are working to root cause the issue but will likely revert this CL that (presumably) causes this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/aosp/platform/system/connectivity/shill/+/1709b45b60b9ea26114ba9643b0a22a5876c3ff6

commit 1709b45b60b9ea26114ba9643b0a22a5876c3ff6
Author: Micah Morton <mortonm@chromium.org>
Date: Tue Jul 31 23:37:25 2018

shill_login_user: Ensure shill user profile dir is owned by shill:shill

We need to chown this dir to be owned by shill:shill even if it already
exists, so that when we update CrOS devices to running shill as
shill:shill (instead of root:root), the dir gets updated to the correct
permissions.

BUG=chromium:867171, chromium:867685 , chromium:865184 , chromium:867680 , chromium:864874 , chromium:865789 , chromium:866041 , chromium:866559 , chromium:866961 
TEST=flash 10820 image to lulu device. log in as user. configure VPN
stuff. flash new 10888 image to lulu and update shill_login_user script.
login and notice that these problems go away.

Change-Id: Ib487d3a36a7b351887e5c101f1e797a0ab21c3b9
Reviewed-on: https://chromium-review.googlesource.com/1153841
Commit-Ready: Micah Morton <mortonm@chromium.org>
Tested-by: Micah Morton <mortonm@chromium.org>
Reviewed-by: Abhishek Bhardwaj <abhishekbh@chromium.org>
Reviewed-by: Micah Morton <mortonm@chromium.org>

[modify] https://crrev.com/1709b45b60b9ea26114ba9643b0a22a5876c3ff6/bin/shill_login_user

Not able to reproduce this issue on 10928.0.0 (Babymega/Coral), hence closing the bug. Will re-open this bug if the issue pops up again.