fix(globalaccelerator-endpoints): add preserveClientIp option for net…

…work loadbalancer

### Issue # (if applicable)

### Reason for this change

preserveClientIp was missing for GlobalAccelerator Endpoints when using a network loadbalancer.

### Description of changes

* add missing network load balancer endpoint prop.

### Description of how you validated changes

Added integration tests.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk-testing/framework-integ/test/aws-globalaccelerator-endpoints/test/integ.globalaccelerator.js.snapshot/integ-globalaccelerator.template.json

@@ -691,6 +691,18 @@
       }
      },
      {
+      "ClientIPPreservationEnabled": true,
+      "EndpointId": {
+       "Ref": "ALBAEE750D2"
+      }
+     },
+     {
+      "EndpointId": {
+       "Ref": "NLB55158F82"
+      }
+     },
+     {
+      "ClientIPPreservationEnabled": true,
       "EndpointId": {
        "Ref": "NLB55158F82"
       }

packages/@aws-cdk-testing/framework-integ/test/aws-globalaccelerator-endpoints/test/integ.globalaccelerator.ts

@@ -38,7 +38,9 @@ class GaStack extends Stack {
       listener,
       endpoints: [
         new endpoints.ApplicationLoadBalancerEndpoint(alb),
+        new endpoints.ApplicationLoadBalancerEndpoint(alb, { preserveClientIp: true }),
         new endpoints.NetworkLoadBalancerEndpoint(nlb),
+        new endpoints.NetworkLoadBalancerEndpoint(nlb, { preserveClientIp: true }),
         new endpoints.CfnEipEndpoint(eip),
         new endpoints.InstanceEndpoint(instances[0]),
         new endpoints.InstanceEndpoint(instances[1]),