Refactor to SimChangeListener class

Test: as follows
    - built (bullhead)
    - flashed
    - booted
    - runtest frameswork-net passes
    - tested wifi-to-mobile tethering, including SIM remove/insert
Bug: 32163131
Change-Id: I6aac9a8f34cfd0079a4433471ec08b9b1ec0d754
1 file changed