cellbroadcast API cleanup

1. define SmsCbConstants inside cellbroadcastService
2. define a filegroup for smsCbConstants to share with
cellbroadcastReceiver
3. TODO delete SmsCbConstants defined in telephony--common
4. delete unused static lib

Bug: 135956699
Test: Build
Change-Id: I9ca0c466b356c307c0c844d6ddec7d2951295f8a
Merged-in: I9ca0c466b356c307c0c844d6ddec7d2951295f8a
3 files changed