Kubernetes : configuring custom influxdb sink for heapster running in kube-system namespace on GKE

I need to configure heapster to send kubernetes cluster metrics to our custom influx db server . For this I tried to edit heapster deployment in kube-system namespace but after some time deployment is getting reverted to original state .
I am using GKE , master version is 1.5.7 and node version is 1.5.6 .