[2/3]Bluetooth: add "Accept all files" option for incoming files via Bluetooth

  This patch will let the OBEX server read "Accept all files" option
before it starts to check mime-type whitelist.
  If not enabled,the check process will go on as usual.
  If enabled,mime-type checking will be skipped.

Change-Id: I056f88246911da0f47da9043187ff3f959315dce

Conflicts:
	src/com/android/bluetooth/opp/BluetoothOppObexServerSession.java