Fix behavior of bootstrap manager after monitoring timeout was reached

StartMonitoring resets monitor_until_ member always.
ContinueMonitoring resets monitor_until_ only for online state as we
don't have timeout in this state.

Removed check for last_configured_ssid.empty() from
UpdateConnectionState because we should shutdown bootstrapping if device
is connected using other interface.

BUG:25463084

Change-Id: I0afd943f4a3ca797b65a51236103ea3d345828d2
Reviewed-on: https://weave-review.googlesource.com/1473
Reviewed-by: Paul Westbrook <pwestbro@google.com>
(cherry picked from commit 65e1f21f13102b076156e2e6a07486c06f5b25d1)
3 files changed