Fix ip address flush on interfaces in bridges for dvr and dvr-ssl model

This patch adds ipflush_onchange: true for interfaces that are members of bridges
to make sure theirs IPs are removed when applying linux.network.interface state
for the following models:
  virtual-mcp-pike-dvr
  virtual-mcp-pike-dvr-ssl

Change-Id: I40410ba0701581e2dbf7622d14ee3918640b07f7
diff --git a/classes/cluster/virtual-mcp-pike-dvr/openstack/gateway.yml b/classes/cluster/virtual-mcp-pike-dvr/openstack/gateway.yml
index 586579c..6ed3f45 100644
--- a/classes/cluster/virtual-mcp-pike-dvr/openstack/gateway.yml
+++ b/classes/cluster/virtual-mcp-pike-dvr/openstack/gateway.yml
@@ -19,3 +19,12 @@
       notification:
         driver: messagingv2
         topics: "notifications"
+  linux:
+    network:
+      interface:
+        primary_interface:
+          ipflush_onchange: true
+        tenant_interface:
+          ipflush_onchange: true
+        external_interface:
+          ipflush_onchange: true