Default to setting secure mode on the integration bridge

Set the fail-mode on the integration bridge to be secure. This means if the agent
is stopped or crashes, and OVS is also restarted, OVS will not program a default
NORMAL action. As soon as the agent is restarted, it will correctly program the
integration bridge.

Change-Id: Icf7e3e14ee747c8ce92c14c95a0a1bbf35986252
Closes-Bug: #1324703
Merge "Default to setting secure mode on the integration bridge"