Make json schema more strict

:Release Notes:
Made setBroadcastTime and other related calls be more strict about
their argumetns

:Detailed Notes:
- Updated schemas to follow new spec.
- Removed unused code.

:Testing Performed:
Desktop build

:QA Notes:

:Issues Addressed:
[GF-42288] setBroadcastTime accepts empty parameter

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Change-Id: Iae4527dbe85bd129d0ef9e9ae33826355f91bc7d
Reviewed-on: https://g2g.palm.com/3654
Reviewed-by: Build Verification
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>