Cisco VPN driver correct reporting for admin state chg

Depends on reference implementation change (81124 review) that will pass VPN
service admin up/down changes to the service driver (for subsequent passing
to the device driver).

This change will save the runtime state of the IPSec connections that have
been removed due to a VPN service down change, so that this can be reported
to the plugin properly. Otherwise, without the change, there is no info
on the downed connection and no change report so the plugin thinks the
connection is still active.

In addition, the status for the VPN service will reflect whether there are
any IPSec connections ACTIVE. If one or more are acive, the service will
be active, otherwise it will be DOWN.

Updated UT to add tests for admin state and status reporting. Also changed
some IPSec create UTs because they were not cleaning up correctly upon test
failures (only seen with a live CSR).

In the future, when the Cisco CSR REST API supports admin up/down support,
the IPSec connections will not be deleted, but instead will be shut down, in
response to an admin down event (and then brought up, for admin up). During
the down time, the state will be reported correctly and no run-time state
recording needed.

Change-Id: I294bfb400c31ef36dfe5d9e85b34845e5aef8515
Closes-Bug: 1291619
(cherry picked from commit c1ccc585bda70925a4cffe617743ef6472fe60c4)
Merge "Cisco VPN driver correct reporting for admin state chg" into milestone-proposed