dragon: Add libbt-vendor in device.mk

Bug: 36810308
Test: build
Change-Id: Id2a77fabcae65d452365ac468009197b7c7dbace
diff --git a/device.mk b/device.mk
index 7aac1b5..ff8dc7e 100644
--- a/device.mk
+++ b/device.mk
@@ -121,6 +121,7 @@
 
 # Bluetooth HAL
 PRODUCT_PACKAGES += \
+    libbt-vendor \
     android.hardware.bluetooth@1.0-impl
 
 # Copy dsp firmware to the vendor parition so it is available when hotwording