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: I23f61e77f6a9a16ce77f7892ba96fd7485c555a4
Change-Id: I23f61e77f6a9a16ce77f7892ba96fd7485c555a4
(cherry picked from commit 750b8b19)