Bluetooth: DUN: Add DUN profile support in Settings APP

It registers service listener for DUN profile with the
BT adapter, and it will track the profile status with
the service listener state chnages.

It also has support for DUN profile connection status
updation and DUN Disconnection from server.

Change-Id: I83d4919821cb095429ff7e73a8974d92c4df086c
Settings: Add Advanced reboot (1 of 2)

This commit adds a setting in Development settings for including options
in the power menu for rebooting into recovery or bootloader, defauled to
off.

When enabled, the Advanced reboot options will only be available once the
device is unlocked.

Change-Id: I72d6df55bf5df251802b321410670646d26c54b0