Added sub id to SmsCbMessage

Added a new field subscription id to SMS
cell broadcast message.

This is the preliminary step of deprecating
CellBroadcastMessage class.

Bug: 144891074
Test: Manual
Merged-In: Ibac8d3e77be15b618dd8b11878c984617614586c
Change-Id: Ibac8d3e77be15b618dd8b11878c984617614586c
(cherry picked from commit 64049c2f)