chore(trait): Migrate the Istio trait to structured serialization
diff --git a/pkg/trait/istio.go b/pkg/trait/istio.go
index 441d92e..2c26a60 100644
--- a/pkg/trait/istio.go
+++ b/pkg/trait/istio.go
@@ -34,9 +34,9 @@
 type istioTrait struct {
 	BaseTrait `property:",squash"`
 	// Configures a (comma-separated) list of CIDR subnets that should not be intercepted by the Istio proxy (`10.0.0.0/8,172.16.0.0/12,192.168.0.0/16` by default).
-	Allow string `property:"allow"`
+	Allow string `property:"allow" json:"allow,omitempty"`
 	// Forces the value for labels `sidecar.istio.io/inject`. By default the label is set to `true` on deployment and not set on Knative Service.
-	Inject *bool `property:"inject"`
+	Inject *bool `property:"inject" json:"inject,omitempty"`
 }
 
 const (