Fix FakeUserHal issues.

FakeuserHal was not working and this CL fixes two issues. One is
the fake property value's timestamp is by default 0 which cause
the write to property store failed. The second is that areaId needs
to be set to 0 when responding to the client.

Test: atest FakeVehicleHardwareTest
test on gcar_emu
adb shell cmd car_service get-initial-user-info COLD_BOOT
adb shell dumpsys android.hardware.automotive.vehicle.IVehicle/default --set 299896583 -a 1 -i 666 1 11
adb shell cmd car_service get-initial-user-info COLD_BOOT
Bug: 260934188

Change-Id: I61d895a15d21308700849acacf39057b1845430f