Implement the case when user inserts / removes pSIM during the SUW.
Bug: 153811431
Bug: 170508680
Test: Manually tested
Change-Id: Iccc3a2fd416ccfb57c3b4f9dc7b32c0b7681c90b
Initial setup for migrating SlotChangehandler from LPA to Settings
Bug: 160819212
Bug: 153811431
Test: Manually tested on Pixel 4 to make sure SlotChangeReceiver can get
slot change events correctly.
Change-Id: Id95f2db875ba08250f4740536742627500b74f0d