InCallUI: fix smartcover always showing  answer fragment

It seems the deleted lines were causing the issue as InCallUI properly handles logic for
showing and hiding the fragment itself.

Change-Id: I1d45b49ae48931adf48faa555296a467373e9247
Signed-off-by: Roman Birg <roman@cyngn.com>
(cherry picked from commit 0c59015fa2be370118723ed0851c2bbd32b7e87b)