cold sim clean up

- add new api to control provisioning notification visibility through
      network agent
- rework on the interaction between carrier app and framework
- code cleanup
- unit test support
- hook pco value into datacallcomplete, enabling test by set sysprop for
  pco values

Bug: 28567303
Change-Id: Id6b9b2aff4c4f128103593aab0bcef1c3a365141