SAP: Make it possible to enforce a 16-digit pin code (5/5)

This change enable the posibility to enforce using a
16-digit pin or MITM for a RFCOMM or L2CAP connection.

This is needed for the SIM access profile.

Change-Id: I6bb2b0dff1ebf4b4f1d8faad97aa7c480000d3ea
Signed-off-by: Casper Bonde <c.bonde@samsung.com>