Add UTC value to getEffectiveBroadcastTime

:Release Notes:
getEffectiveBroadcastTime now returns UTC-like value for broadcast
local time.

:Detailed Notes:
Some apps need UTC time for constructing date-time objects. Since
those constructors will work according to time-zone selected
system-wide, but we should show broadcast local time. We need to
re-construct UTC from broadcast local time with active TZ rules. For
that reason we call that result "adjustedUtc".

:Testing Performed:
Tested on desktop build

:QA Notes:

:Issues Addressed:
[GF-41588] we need UTC string back in getEffectiveBroadcastTime

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Change-Id: I37c4ef9c042ac3741ad7299ae8b5169ac7944bd3
Reviewed-on: https://g2g.palm.com/3621
Reviewed-by: Keith Derrick <keith.derrick@lge.com>
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Build Verification