Add thermal service into system_server

This system service will listen to ThermalHAL for throttling events and
take actions accordingly, e.g. shutdown device and/or sending
notification to registered listeners to IThermalSerivce.

Bug: 79443945
Bug: 118510237
Bug: 111086696
Bug: 116541003
Test: Boot and test callback on ThermalHAL 1.1
Test: Boot and test callback on ThermalHAL 2.0
Test: Kill ThermalHAL process
Test: Change device threshold to trigger shutdown
Change-Id: I1f4066c9f1cf9ab46c1738a0a4435802512e4339