OBEX: Avoid BluetoothExt process kill for active MAP or FTP Session.

StartForeground() API during MAP or FTP session CONNECT mark the process
in foreground and avoid it being getting killed from Android process
management. StopForeground() API for corresponding session DISCONNECT
mark it to original priority or background.

Ongiong Notifications are supplied to indicate the Acitve FTP
or MAP sessions to USER in Status Bar.

Change-Id: I177c07e57a7382fced83da906d6a61ee5176e189
CRs-fixed: 547554
Merge "OBEX: Avoid BluetoothExt process kill for active MAP or FTP Session."
Merge branch 'master' of git://codeaurora.org/platform/vendor/qcom-opensource/bluetooth into cm-10.2
Merge remote-tracking branch 'cm/cm-10.2' into jb-4.3