CMB-1022: Ensure that the negative sign remains on the left side of numeric values  in RTL.

Issue
-------
The negative sign is displayed on the right side of numeric values in RTL.

Fix
----
We specify `direction:ltr` for `moon.IntegerPicker` to ensure the negative sign remains on the left side of numeric values.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>