vpn-manager: Use LCP echo to keep session alive

Instead of using the "idle" configuration option to automatically
shut down connections, use the "lcp-echo-interval" and
"lcp-echo-failure" to actively monitor the connection state
instead of shutting down idle connections.


Change-Id: I82060e4b709e5ae017197a502c9782fde18b216e
Reviewed-on: https://chromium-review.googlesource.com/199571
Reviewed-by: Ben Chan <benchan@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
2 files changed