OCPBUGS-61858: Use pointer type for HTTPKeepAliveTimeout in IngressController API

This commit addresses the problem of the creation of the default IngressController
without `HTTPKeepAliveTimeout` tuning option by the cluster ingress operator:
"IngressController.operator.openshift.io \"default\" is invalid: spec.tuningOptions.httpKeepAliveTimeout: Invalid value: \"string\": httpKeepAliveTimeout must be greater than or equal to 1 millisecond"

Author: alebedev87

operator/v1/types_ingress.go

@@ -1912,7 +1912,7 @@ type IngressControllerTuningOptions struct {
 	// +kubebuilder:validation:MinLength=1
 	// +kubebuilder:validation:MaxLength=16
 	// +optional
-	HTTPKeepAliveTimeout metav1.Duration `json:"httpKeepAliveTimeout,omitempty"`
+	HTTPKeepAliveTimeout *metav1.Duration `json:"httpKeepAliveTimeout,omitempty"`
 
 	// tlsInspectDelay defines how long the router can hold data to find a
 	// matching route.