Implementation of OOB PTS cert test cases

SM/SLA/SCOB/BV-02-C
SM/SLA/SCOB/BV-03-C
SM/MAS/SCOB/BV-04-C

This patch also fixes how we wait for disconnection event. Instead of
using fixed timeout, wait for actual disconnection.

Tag: #gd-refactor
Bug: 155399771
Test: gd/cert/run --host LeSecurityTest
Change-Id: I6d132334a8f435f2fbc10a1fc010ace06134abae