cold sim clean up

- add a new field: provisioningNotificationEnabled from NetworkMisc. set
  to false if we want to hide "sign in" notification and placed
  carrier-specific notification instead. it is set on connect, once set,
  it is carrier-app's responsibility to post new UI to users
- rework on the interaction between carrier app and framework
- code cleanup
- unit test support

Bug: 28567303
Change-Id: Ic84db7ffbb920d15344717f104496d3cb82e1a85