Keep light on if interacting

This makes it possible to do a bunch of things without
having to keep touching the light button.

I don't really see any downside with this. If you want
the light to go off, just stop touching buttons.

watch-library/simulator/main.c

@@ -89,6 +89,7 @@ void main_loop_sleep(uint32_t ms) {
     main_loop_set_sleeping(true);
     emscripten_sleep(ms);
     main_loop_set_sleeping(false);
+    animation_frame_id = ANIMATION_FRAME_ID_INVALID;
 }
 
 bool main_loop_is_sleeping(void) {