vehicle hal further clarification / HVAC update

- added HVAC_POWER_ON property
- added special INT / FLOAT OUT_OF_RANGE values for
  max / min / off state
- added dump call for debugging: necessary for debugging
- clarified subscribe behavior for ON_CHANGE type
  VNS will make additional get call for checking initial
  state.
- added clarification on possible -EAGAIN for set call
- added mute flag to allow muting radio from android

bug: 27721415
bug: 28022648
bug: 27971383
bug: 27971578

Change-Id: Ie9a7334b86ab53174b91a4dc651fd87ca17af3d9
diff --git a/modules/vehicle/vehicle.c b/modules/vehicle/vehicle.c
index d8aa2cb..a26f27c 100644
--- a/modules/vehicle/vehicle.c
+++ b/modules/vehicle/vehicle.c
@@ -526,6 +526,11 @@
     }
 }
 
+static int vdev_dump(struct vehicle_hw_device* device UNUSED, int fd UNUSED) {
+    //TODO
+    return 0;
+}
+
 /*
  * The open function is provided as an interface in harwdare.h which fills in
  * all the information about specific implementations and version specific
@@ -557,6 +562,7 @@
     vdev->vehicle_device.set = vdev_set;
     vdev->vehicle_device.subscribe = vdev_subscribe;
     vdev->vehicle_device.unsubscribe = vdev_unsubscribe;
+    vdev->vehicle_device.dump = vdev_dump;
 
     *device = (hw_device_t *) vdev;
     return 0;