Bluetooth: Fix setting app stoped when unpair device

Revert gerrit: Bluetooth DUT discovery the correct adapter name.
If set alias name as null, later it will call setAlias function,
it does't check input string and call function getBytes() on the
null object.

CRs-Fixed: 1082835
Change-Id: I6c6c9c6427517993c7288994e2ae0142caac43c2