Dock on touch screen does not handle touch events correctly

If you touch an icon on the dock using a touch screen, the dock performs duplicate actions for a single touch event.

1. Touching the app-grid icon on the dock with your finger causes the "applications dash" to appear, and quickly disappear, as if you had left-clicked on the app-grid icon *twice* using a mouse button.

2. Touching any favorites icon on the dock with your finger causes the selected application to open *two* instances, as if you had left-clicked on the app-grid icon twice using a mouse button.

THIS ONLY AFFECTS UBUNTU-DOCK
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This only happens when using the touch screen to interact with the dock. Using a mouse or track-pad works as expected.

The top-bar behaves as expected, as well, when using the touch screen. For example, touching the Activities label ovens the "dash overview" as expected; touching the notifications area on the top bar opens the notifications/calendar as expected; touching the indicator icons behave as expected as well.

Interacting with open applications using the touch screen also works as expected. Applications respond to touch events as if a single event was generated.

UBUNTU DOCK
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Only the ubuntu-dock acts as if it received two (or more) touch events for each single touch action.

EXPECTED BEHAVIOR
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Ubuntu dock should respond as if it received a single click event, for each single touch event.

ADDITIONAL INFORMATION
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If I touch the "Action" item at the top left of the desk-top, the overview appears. THEN, if I touch an icon in the dock, it behaves correctly.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-shell-extension-ubuntu-dock 0.9.1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: GNOME
Date: Sun May 6 20:35:07 2018
InstallationDate: Installed on 2018-05-05 (1 days ago)
InstallationMedia: Ubuntu 18.04.0 2018.05.03 LTS "Custom Bionic Beaver"
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-shell-extension-ubuntu-dock
UpgradeStatus: No upgrade log present (probably fresh install)