Schematize Car system properties

Properties accessed across partitions are now schematized and will
become APIs to make explicit interfaces among partitions.

Bug: 117924132
Test: mma -j
Change-Id: Ie3a794ac071ff4a2612ebc89ba75926e3661a00a
(cherry picked from commit 98e51614453816e080534a72ec808a96d92e4610)