Build BluetoothExt

* we have this repo but didn't build it

Change-Id: Ie3074509946babb651141c7f91d9de2950118d14
Signed-off-by: houst0nn <houstonn@gmail.com>
Allow override of DUN settings

Allow override of system DUN settings by setting
persist.sys.dun.override
to one of the following values:
2 = not set, 0 = DUN not required, 1 = DUN required
If the prop is not set or is set to an invalid value the system setting
will be used.

Change-Id: I55066334d66ce24a485fbbb2cc1e6450c1025507