Implement Presence Broadcast.

Bug: 218187205
Test: atest NearbyUnitTests
Change-Id: Idaafc590e1ee12abe29699013098435ea26c400c
(cherry picked from commit 7ab6e30f394311eeb233445d4e811c67324bc6f6)
Merged-In: Idaafc590e1ee12abe29699013098435ea26c400c
11 files changed
tree: 64fed2d20c56d81982968fc8704215eb10b452e9
  1. nearby/