input: encrypt on receive conn req if classic_bonded_only

input: encrypt on receive conn req if classic_bonded_only

According to bluetooth HID1.1 spec, section 5.4.3.5.3:
If the Bluetooth HID Host is bonded to a Bluetooth HID device:
If encryption is not already enabled, the Bluetooth HID Host shall
enable encryption with the Bluetooth HID device before sending an
L2CAP Connect Response with a result code of “Connection Successful”
(0x0000) after an L2CAP Connect Request is received.

This patch raises the security level to medium when listening for
incoming connection if the flag classic_bonded_only is set,
effectively starting encryption.

Signed-off-by: Anuj Jain <anuj01.jain@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>