Comment 5 for bug 1818473

With the trick described in the test instructions:
Prior to the update even when restarting the service:
[2019-03-11T08:31:47.052Z] [ warning] [resolutionCommon] resolutionCheckForKMS: No system support for resolutionKMS.

Upgrade:
sudo apt install open-vm-tools-desktop open-vm-tools
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  xdg-utils
Recommended packages:
  xserver-xorg-input-vmmouse
The following packages will be upgraded:
  open-vm-tools open-vm-tools-desktop
2 upgraded, 0 newly installed, 0 to remove and 39 not upgraded.
Need to get 672 kB of archives.
After this operation, 6144 B of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu bionic-proposed/universe amd64 open-vm-tools-desktop amd64 2:10.3.5-7~ubuntu0.18.04.1 [129 kB]
Get:2 http://archive.ubuntu.com/ubuntu bionic-proposed/main amd64 open-vm-tools amd64 2:10.3.5-7~ubuntu0.18.04.1 [543 kB]
Fetched 672 kB in 1s (482 kB/s)
dpkg: considering deconfiguration of open-vm-tools-desktop, which would be broken by installation of open-vm-tools ...
dpkg: yes, will deconfigure open-vm-tools-desktop (broken by open-vm-tools)
(Reading database ... 116821 files and directories currently installed.)
Preparing to unpack .../open-vm-tools_2%3a10.3.5-7~ubuntu0.18.04.1_amd64.deb ...
De-configuring open-vm-tools-desktop (2:10.3.0-0ubuntu1~18.04.3) ...
Unpacking open-vm-tools (2:10.3.5-7~ubuntu0.18.04.1) over (2:10.3.0-0ubuntu1~18.04.3) ...
Preparing to unpack .../open-vm-tools-desktop_2%3a10.3.5-7~ubuntu0.18.04.1_amd64.deb ...
Unpacking open-vm-tools-desktop (2:10.3.5-7~ubuntu0.18.04.1) over (2:10.3.0-0ubuntu1~18.04.3) ...
Processing triggers for ureadahead (0.100.0-20) ...
Setting up open-vm-tools (2:10.3.5-7~ubuntu0.18.04.1) ...
Processing triggers for libc-bin (2.27-3ubuntu1) ...
Setting up open-vm-tools-desktop (2:10.3.5-7~ubuntu0.18.04.1) ...
Processing triggers for systemd (237-3ubuntu10.13) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...

service right after upgrade install has the new drop in snippet:
$ systemctl cat open-vm-tools
# /lib/systemd/system/open-vm-tools.service
[Unit]
Description=Service for virtual machines hosted on VMware
Documentation=http://open-vm-tools.sourceforge.net/about.php
ConditionVirtualization=vmware
DefaultDependencies=no
Before=cloud-init-local.service
After=vgauth.service
After=apparmor.service
RequiresMountsFor=/tmp
After=systemd-remount-fs.service systemd-tmpfiles-setup.service

[Service]
ExecStart=/usr/bin/vmtoolsd
TimeoutStopSec=5

[Install]
WantedBy=multi-user.target

# /lib/systemd/system/open-vm-tools.service.d/desktop.conf
[Service]
ExecStartPre=-/sbin/modprobe vmwgfx

The log now is happy for the KMS plugin
[2019-03-11T08:37:35.074Z] [ message] [resolutionCommon] resolutionCheckForKMS: dlopen succeeded.
[2019-03-11T08:37:35.076Z] [ message] [resolutionCommon] resolutionCheckForKMS: System support available for resolutionKMS.

Setting verified