Add plumbing from settings to gesture properties

Because we don't have the Android curve parameters yet (or the code to
put them into the custom curve gesture properties), the fifteen
different speed settings get mapped onto the five ChromeOS curves
built-in to the gestures library

Bug: 251196347, 247080509, 265798483
Test: Use settings command in ADB shell to change values
Change-Id: I414d6e63c56d8e42c5848ca4aa150510956c70e3