Follow-on to #5301

@katelem24 reports on the community site https://community.software.sil.org/t/keyman-15-beta-feedback/5755/29

Once in a while longpress pop-ups appear when one has not long-pressed the key, and will not go away except you press another key or switch layer. Sometimes they block the way to required keys, and moving the insertion point will not remove the pop-ups.

more screenshots on the community site...

Configuration

Apps Used:
Google Keep, Google Chrome, Google Notebook, Word Web dictionary.

Keyman Version:
15.0.225 and 15.0.228

Platform:
Android, 8.1

Device:
Tecno POP 2

On investigation, it seems the GestureDetector isn't always getting the final ACTION_UP which dismisses all the popups.