Bluetooth: Added a property to have the tethering setting persist

Added a property to have the tethering setting persist, so that
in the BT on/off the value can be restored and based on the value
tethering settings will be restored/altered.

Change-Id: I814641b2150377838d55378ff06b5cd80343b35f
CRs-fixed: 506194
Accept all mimetypes for inbound bluetooth file transfers

(cherry picked from commit d4505e0801e8ee28b2373985234bc3fdd40d3213)

Change-Id: I5ad0b6dc8575c0fd337aa4a045051a5e0de0eb77
handleCpbsCommand was incorrectly sending two responses which broke phonebook sync with Audi 2G MMI

Change-Id: I0c68c3806379fda6d516b070da9750d8ffab4ad5
Allow sending/receiving of APK files over bluetooth

Change-Id: Ibfc795005dc9c8054b044112feff4a17c24c5e27