GitLab

- Remove kConnecting and add timer to track requested state in find my
device controller.
- Edit FakeFindMyDeviceController to use for unit test.
- Remove a TODO in enable hotspot since unnecessary.

BUG=1106937,1126208

Change-Id: Ic5a5dd2126313b2b22885ce8a23237fe281e762a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2446815
Commit-Queue: Andre Le <leandre@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813919}