Add vehicle properties to integrate car watchdog

- WATCHDOG_ALIVE to tell car watchdog is alive
- WATCHDOG_TERMINATED_PROCESS to pass a process information terminated
- VHAL_HEARTBEAT to signal that VHAL is alive
by car watchdog

Bug: 159912961
Test: build okay
Change-Id: I0498d525aa6465199f0b0011600234feaf7c4aa4