Sensor: use FlattenableUtils::align

Since it memsets skipped over memory now.

Bug: 141890807
Test: boot, check buffer is zero'd here

[basilgello: Back-ported to 14.1:
 - lib/sensor/Sensor.cpp -> lib/gui/Sensor.cpp]

Signed-off-by: Vasyl Gello <vasek.gello@gmail.com>

Change-Id: Ieb3cd90215a3ccc1dc43365ecde251a50db08553
(cherry picked from commit d58cf5ac)
(cherry picked from commit dbd0eecf)