Allow CarService to read VHAL instance name

Bug: 143779011
Test: boot with modified instance name variable

Change-Id: Ic86b9c67e2f50087eb8fc14417394b4475560d8b
diff --git a/car_product/sepolicy/private/carservice_app.te b/car_product/sepolicy/private/carservice_app.te
index 6e65a8f..a272e4a 100644
--- a/car_product/sepolicy/private/carservice_app.te
+++ b/car_product/sepolicy/private/carservice_app.te
@@ -67,3 +67,6 @@
 
 set_prop(carservice_app, ctl_start_prop)
 unix_socket_connect(carservice_app, dumpstate, dumpstate)
+
+# Allow reading vehicle-specific configuration
+get_prop(carservice_app, vehicle_hal_prop)