[BJv2, 95%] Modify "swipe back to clock" to use swipe up to down instead of Lt to Rt.

ok, gpt4 worked,
originally after i read the manual i'll use

let swipeHandler = ( 0 , dir) => {

but gpt4 is weak, but still stronger than layman.

so should use let swipeHandler = ( _ , dir) => {

may be no need to upload this subtle thing to the bangle store,
but this will make "swipe back to clock" use swipe Up to Down, instead of Lt to Rt;
so now you can at the same stime use "swipe back" swipe Lt to Rt for 1 step back.