xapi1 as the default ovs_integration_bridge can be incorrect as it is
dependent on the environment. xapi<n> are internal bridges that are
incrementally defined from zero. Operators should set this config value
to the integration bridge used between all guests and the compute host
in their environment.
UpgradeImpact
Change-Id: If463936553cc663fd0bd018ccc9b8395bbdff6d9