veyron/lib/bluetooth: Fix build on Mac by adding a missing build directive.
veyron/lib/bluetooth: Fix build on Mac by adding a missing build directive.

Change-Id: Ie999e43ca093bb513c6f280328358262222fd02c

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref