Send LE Set Random Address and check response
[Problem] HCI command Tx timeout happens.
[Cause & Measure] Vendor command is sent before Command complete event comes
for LE Set Random Address. It causes bluetooth chip's malfunction.
This commit fixs to check the response about LE Set Random Address. So
that next vendor command is sent after LE Set Random Address is
processed properly by chipset.
[Checking Method] Turn on Bluetooth > Start advertising
Change-Id: Ie757398be6d8ad71da1cc23b72ac132789df9e49