Add ReplaceRoute in ControllersPolicy

AwsCluster stuck at deleting state throwing Error due to missing permission in Controller Policy.

its required for

https://github.com/AmitSahastra/cluster-api-provider-aws/blob/318413aaded7f7aece86f315af7058bd956ec488/pkg/cloud/services/network/routetables.go#L89
```
Error :   [2] [capa-controller-manager-c754997c6-9nxx8] 1 awscluster_controller.go:209] controller/awscluster "msg"="failed to reconcile network" "error"="failed to replace outdated route on route table \"rtb-
```

Author: AmitSahastra

cmd/clusterawsadm/cloudformation/bootstrap/cluster_api_controller.go

@@ -97,6 +97,7 @@ func (t Template) ControllersPolicy() *iamv1.PolicyDocument {
 				"ec2:DeleteInternetGateway",
 				"ec2:DeleteNatGateway",
 				"ec2:DeleteRouteTable",
+				"ec2:ReplaceRoute",
 				"ec2:DeleteSecurityGroup",
 				"ec2:DeleteSubnet",
 				"ec2:DeleteTags",