Initial change on carrier signal filtering

 - support new carrier configs with two signal list per carrier app
 - support new broadcast mechanism to comply with background-check restriction on O.
 - add carrier action agent for dispatching carrier actions

Bug: 30958215
Test: runtest --path
frameworks/opt/telephony/tests/telephonytests/src/com/android/internal/telephony/CarrierSignalAgentTest

Change-Id: I4e9e2f56e991e9d6753f8d7e877add5ada595972