Proximity Auth: Remove kEnableUnifiedMultiDeviceSetup flagging.

R=hansberry@chromium.org

Bug: 899324
Test: none
Change-Id: I45d7f04e97a914596cd1bffd5e2ea73543064810
Reviewed-on: https://chromium-review.googlesource.com/c/1329889
Commit-Queue: James Hawkins <jhawkins@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607051}
4 files changed