Bluetooth: start/stop bt-dun service based on DUN profile status

Start/Stop bt-dun service based on DUN profile status property
"bluetooth.dun.status".

Renamed the SAP profile property to "ro.bluetooth.sap" and
DUN profile property to "ro.bluetooth.dun".

Change-Id: Ie47413492cc3fb2b1dacf83b07c52fb51e77e803
Merge "Bluetooth: start/stop bt-dun service based on DUN profile status"