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
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:25a3fcd487c799d5d9029b8646159a0b10143d97)
Merged-In: I369a8fdd675eca731a7a488ed6a2be645058b795
Change-Id: I369a8fdd675eca731a7a488ed6a2be645058b795