Update helm to update API's used for Deployments and Sevices to apps/v1

[akodali18]

Describe the bug helm chart to installation will fail on kubernetes version 1.16 and above

With 1.16 version of kubernetes, Deployment in the extensions/v1beta1, apps/v1beta1, and apps/v1beta2 API versions is no longer served.

In the new api i.e. apps/v1, for Deployment - spec.selector is now required and immutable after creation; use the existing template labels as the selector for seamless upgrades Refer to https://kubernetes.io/blog/2019/07/18/api-deprecations-in-1-16/

We Need to modify out helm charts to include spec.selector in Deployment, specifically modify it to something like :

---
# Source: wavefront/templates/adapter.yaml
# deployment for adapter wavefront
apiVersion: apps/v1
kind: Deployment
metadata:
  name: wavefront
  namespace: wavefront-istio
  labels:
    app: wavefront
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wavefront
  template:
    metadata:
      labels:
        app: wavefront
      annotations:
        sidecar.istio.io/inject: "false"
        scheduler.alpha.kubernetes.io/critical-pod: ""
    spec:
      containers:
      - name: wavefront
        image: vmware/wavefront-adapter-for-istio:0.1.2
        imagePullPolicy: Always
        ports:
        - containerPort: 8000
--- 

Steps to reproduce the bug {{ Minimal steps to reproduce the behavior }} Just use existing helm chart to install the adapter on K8s version 1.16 and above.

Version {{ What version of Istio and Kubernetes are you using? Use istioctl version and kubectl version }} This can be seen using any kubernetes version 1.16 and above.