OCPBUGS-43692: Fix LB Type Defaulting with ProviderParameters Set

In the case that `alreadyAdmitted` was true and the IngressController's
spec had `providerParameters` set, `setDefaultProviderParameters`
incorrectly forced the LB type to `Classic`.

This fix relocates the `alreadyAdmitted` check to the logic responsible
for mutating the LB type, rather than applying it to the logic that
determines the `defaultLBType` value.

pkg/operator/controller/ingress/controller.go

@@ -701,15 +701,15 @@ func setDefaultProviderParameters(lbs *operatorv1.LoadBalancerStrategy, ingressC
 		}
 		lbs.ProviderParameters.Type = provider
 		defaultLBType := operatorv1.AWSClassicLoadBalancer
-		if p := ingressConfig.Spec.LoadBalancer.Platform; !alreadyAdmitted && p.Type == configv1.AWSPlatformType && p.AWS != nil {
+		if p := ingressConfig.Spec.LoadBalancer.Platform; p.Type == configv1.AWSPlatformType && p.AWS != nil {
 			if p.AWS.Type == configv1.NLB {
 				defaultLBType = operatorv1.AWSNetworkLoadBalancer
 			}
 		}
 		if lbs.ProviderParameters.AWS == nil {
 			lbs.ProviderParameters.AWS = &operatorv1.AWSLoadBalancerParameters{}
 		}
-		if len(lbs.ProviderParameters.AWS.Type) == 0 {
+		if len(lbs.ProviderParameters.AWS.Type) == 0 && !alreadyAdmitted {
 			lbs.ProviderParameters.AWS.Type = defaultLBType
 		}
 		switch lbs.ProviderParameters.AWS.Type {