Dynamically allocate/de-allocate objects upon multi-SIM onfig changes.

This is part of large effort to not use getSupportedModemCount upon
object allocations, but to use getActiveModemCount, and re-allocate
or de-allocate when it changes (multiSimConfigChange).

This CL involves:
MultiSimSettingController
ProxyController
SubscriptionInfoUpdater
CatService

Bug: 142514392
Test: unittest
Change-Id: If525f4c49cf7d3ded85543243af221550fe0a8f7