[2/4] Port face unlock feature

Also add a flag to opt-out

Change-Id: I9d4bb7174d28ca067665893a8096b3176a5aa7a6
diff --git a/config/common.mk b/config/common.mk
index a4235a0..47c079f 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -182,6 +182,16 @@
 # Google Audio
 $(call inherit-product-if-exists, frameworks/base/data/sounds/GoogleAudio.mk)
 
+# Face Unlock
+TARGET_FACE_UNLOCK_SUPPORTED := false
+ifneq ($(TARGET_DISABLE_ALTERNATIVE_FACE_UNLOCK), true)
+PRODUCT_PACKAGES += \
+    FaceUnlockService
+TARGET_FACE_UNLOCK_SUPPORTED := true
+endif
+PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
+    ro.face.moto_unlock_service=$(TARGET_FACE_UNLOCK_SUPPORTED)
+
 # Bliss Versioning System
 -include vendor/bliss/config/versions.mk