Fix an authentication bypass bug in SMP

When pairing with BLE legacy pairing initiated
from remote, authentication can be bypassed.
This change fixes it.

Bug: 251514170
Test: m com.android.btservices
Test: manual run against PoC
Ignore-AOSP-First: security
Merged-In: Id36c06beb13bcbc9b499ef59f6d4e43ac616da10
Change-Id: I369a8fdd675eca731a7a488ed6a2be645058b795