input: change touchpad scrolling and tap-to-click defaults

I'd had them default to false when I added them, but they should
actually be true by default (i.e. tap to click should be enabled, and
moving two fingers upwards on the touchpad should scroll down).

Bug: 267653650
Test: on a device without touchpad_natural_scrolling setting set, check
      scroll direction is "natural" and tap-to-click works
Test: atest inputflinger_tests
Change-Id: I7d07d599709241460da47d714b221583a7099fb0