Fixed some metadata for v1.12.4 release

Author: Bennett Sala

config/helm/appmesh-controller/Chart.yaml

@@ -1,8 +1,8 @@
 apiVersion: v1
 name: appmesh-controller
 description: App Mesh controller Helm chart for Kubernetes
-version: 1.12.3
-appVersion: 1.12.3
+version: 1.12.4
+appVersion: 1.12.4
 home: https://github.com/aws/eks-charts
 icon: https://raw.githubusercontent.com/aws/eks-charts/master/docs/logo/aws.png
 sources: