bluetooth: allow TUNGETIFF TUNSETIFF

system/sepolicy commit 619c1ef2 started
enforcing ioctl whitelisting requirements for /dev/tun. Bluetooth needs
the ability to issue TUNSETIFF on /dev/tun, so allow access. We also
allow access to TUNGETIFF for good measure.

Addresses the following denial:

avc: denied { ioctl } for comm=425420536572766963652043616C6C path="/dev/tun" dev="tmpfs" ino=20047 ioctlcmd=0x54ca scontext=u:r:bluetooth:s0 tcontext=u:object_r:tun_device:s0 tclass=chr_file permissive=0

Test: policy compiles
Change-Id: Ie4c138fc774373cec266c59de6663db147d60423