Can't double-tap on Linux touchscreen device

[xuvatilavv]

Possibly related: #8151

Godot version:
3.1.1 Stable

OS/device including version:
Ubuntu 19.04 on a Surface Pro 4
I'm also using a kernel patch from https://github.com/jakeday/linux-surface for more consistent touchscreen support on this device.

Issue description:
Can't double-tap to open items in any dialog provided by Godot. I've tested the Project Manager, an "Open a File" dialog in the editor settings, and a FileDialog object running inside a game.
What happened:
I double-tap an entry in a dialog using my touchscreen. On the first tap the item is highlighted, and any further taps have no effect.
What was expected:
I double-tap an entry in a dialog using my touchscreen. On the first tap the entry is highlighted, and on the second tap that entry is loaded/opened.

Steps to reproduce:

1. Open the Godot Project Manager
2. Double-tap on a project using the touchscreen
3. The project is highlighted but doesn't open

A key difference between this issue and #8151 is that I don't have any problem tapping "open" to open the file in the dialog, as was reported there.