Add unique program identifier for broadcast radio

Added unique program identifier in program selector to uniquely specify
DAB (and other technonlogies in the fulture) stations with the same
primary id but different ensemble or frequency values in radio manager
and broadcast radio service.

Bug: 273967346
Test: atest ProgramSelectorTest

Change-Id: I8ba800d0f8e0a2f1a65dd47be47d6564c8c608cd