Fix vertical gesture touch calculations

- Silence HALO touch point was below the Silence HALO marker. (fixed)
- Dismiss (single) notification could be activated while still touching HALO,
  before reaching the dismiss notification marker. (fixed)

Change-Id: I52aa67120a0ea07f7ce134588c276684bb068d03
Signed-off-by: Dan Trifan <jimsth@gmail.com>