Change the logic to check car idleness

- Following the change of device idleness checking, car idleness
tracker considers screen on to determine idleness.
- The condition to get idle in automotive is 1) garage mode is started,
or 2) screen is off and idle is triggered.
- If idleness is forced or garage mode is running, it is considered idle
by car idleness tracker, regardless of screen on/off.

Bug: 182492612
Test: atest android.jobscheduler.cts.IdleConstraintTest
Change-Id: I15e78157c6b1539086e9b39354e5da51186c6535