OSDOCS-13634: Updated 4.18 RN table for br-ex

Author: dfitzmau

Diff for: release_notes/ocp-4-18-release-notes.adoc

@@ -2564,8 +2564,8 @@ In the following tables, features are marked with the following statuses:
 |General Availability
 
 |Customized `br-ex` bridge needed by OVN-Kuberenetes to use NMState
-|Technology Preview
-|Technology Preview
+|General Availability
+|General Availability
 |General Availability
 
 | Live migration to OVN-Kubernetes from OpenShift SDN