Modified zero click filtering to allow separate buttons to work.

Added a check in the initialization of the immediate interpreter
to set the zero click property based on the state of the
is_button_pad hardware property. This should preserve the original
fix for touchpads with faulty switches whilst enabling touchpads
with separate buttons to also work correctly.
Also added a unit test to test both expected behaviors.

BUG=b:182585510
TEST=check the unit tests still build and pass

Change-Id: I5569996fcdb366c00418555277c02c19330d2368
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/gestures/+/2763142
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Tested-by: Pete Brown <peterjbrown@google.com>
Commit-Queue: Pete Brown <peterjbrown@google.com>
3 files changed