Install our libbluetooth3 into rootfs

Something in DEBOOTSTRAP_EXTRA installs upstream libbluetooth3 so
that dependency is already satisfied without installing ours.
While our bluez was alreadu getting installed, call it out
explicitly to avoid accidental breakage in the future if the
bootstrap base changes.

Change-Id: I7add6be47c0b90470210d701c6038b5a36425c09
diff --git a/rootfs.mk b/rootfs.mk
index 971f1b1..6ac3c0e 100644
--- a/rootfs.mk
+++ b/rootfs.mk
@@ -31,6 +31,7 @@
 	aiy-board-tools \
 	aiy-board-wlan \
 	bluetooth \
+	bluez \
 	gstreamer1.0-alsa \
 	gstreamer1.0-plugins-bad \
 	gstreamer1.0-plugins-base \
@@ -44,6 +45,7 @@
 	imx-mkimage \
 	imx-vpu-hantro \
 	imx-vpuwrap \
+	libbluetooth3 \
 	libdrm2 \
 	libdrm-vivante \
 	libegl1-mesa \