pbnjson error handling

pass detail reason in case required key missing

[GF-2816] pbnjson error handling
Open-webOS-DCO-1.0-Signed-off-by: seokjun.lee <sseokjun.lee@lge.com>

Change-Id: Ia1e10df5dac920ffec10f74d55a3951e63a7e2e6