Fix duplicate devices when multiple mediums scanning requested

The dedupuing logic was already in place, but there was a race
due to managin the list of devices from different threads.

Test: using wear app ensure dup device reproduses without CL, and not with it
Fixes: 160870456
Change-Id: I1526199e8e4fb4b8f7d7f306e9e676359cdca516
2 files changed