Refactor more keys menu framework (part 3)

Make it possible to re-enter gesture input even after triggering the long-press
menu. This is useful for new users who may pause at the start of a word. Works
for both single and bi-manual gestures.

Bug: 7595193
Change-Id: Ieaecfd5385ed6c10ae9347b99c2e35a0de5e895d