LatinIME: disable gesture input support

The gesture decoder requires libjni_latinimegoogle.so, but this
proprietary file is only available for armv7 devices.

Disable gesture support, which prevents force-close errors
when performing a swipe motion in the keyboard.

(cherry picked from commit 28e8cc96e35ad10ceea30e05da202180c642eec4)

Change-Id: Ie283e961f340f0fe229e8b881a7596f97966865a