Fix false negative for MojDecimalTest

:Release Notes:
Fixed false negative for MojDecimalTest caused by decimal to double
conversion.

:Detailed Notes:

:Testing Performed:
MojTestCore

:QA Notes:

:Issues Addressed:

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>

Change-Id: I627b744739913671ee3ab3f0359bfbea55c54635
Reviewed-on: https://g2g.palm.com/3258
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Roger Stringer <roger.stringer@lge.com>