Add vehicle hal.

- vehicle hal is used for supporting car specific features.
- Each property can be written (=set), read (=get), or subscribed.
- Each property has configuration informaiton to tell what that property
  is and how it can be accessed.
- also adding dummy hal implementation.

bug: 25183740

Change-Id: Ib1cc1c11540f156db73552f2a18a8efb361002af
diff --git a/modules/Android.mk b/modules/Android.mk
index 9f7e5f0..4f30d3c 100644
--- a/modules/Android.mk
+++ b/modules/Android.mk
@@ -1,4 +1,4 @@
 hardware_modules := gralloc hwcomposer audio nfc nfc-nci local_time \
 	power usbaudio audio_remote_submix camera usbcamera consumerir sensors vibrator \
-	tv_input fingerprint input
+	tv_input fingerprint input vehicle
 include $(call all-named-subdir-makefiles,$(hardware_modules))