[appmesh-gateway] nodeSelector indentation wrong

[yanwsh]

Describe the bug
I am trying to add nodeSelector, but it throws error from k8s. I think the indentation is wrong.

https://github.com/aws/eks-charts/blob/master/stable/appmesh-gateway/templates/deployment.yaml#L71

Steps to reproduce
add code

    const gatewayChart = new HelmChart(this, 'AppMeshGatewayHelmChart', {
      cluster,
      namespace,
      repository: 'https://aws.github.io/eks-charts',
      chart: 'appmesh-gateway',
      release: 'appmesh-gateway',
      version: '0.1.5',
      values: {
        nodeSelector:{
            nodeType: 'system',
        },
      },
    });

throw exception:

unable to build kubernetes objects from release manifest: error validating "": 
error validating data: ValidationError(Deployment.spec.template.spec): 
unknown field "nodeType" in io.k8s.api.core.v1.PodSpec\n' 

Expected outcome
should not throw error

Environment

• Chart name: appmesh-gateway
• Chart version: 0.1.5
• Kubernetes version: 1.19
• Using EKS (yes/no), if so version? yes

Additional Context: