Dell Precision 5550: Mouse drag lock bug

Works on generic Ubuntu 20.04.

Open a terminal and type xinput for a list of devices. Then xinput disable <id> the ELANxx device.

$ xinput disable 15

Swipe gently on the screen and then reenable touchscreen

$ xinput enable 15

Repeat if necessary.

[post #47 on https://bugs.launchpad.net/ubuntu/+source/rapidsvn/+bug/402892]