Periodic full-syncs are just reconcile loops just in case somehow
the dataplane has drifted, however, they have an important cost on large
clusters.
We can avoid to perform full-sync if kube-proxy is in the "largecluster"
mode, we are already doing some optimization, so it is reasonable to
avoid the penalty of a full sync for a "just in case" operation.
Signed-off-by: Antonio Ojea <aojea@google.com>