Add the app/name label to services and primary deployment

[stefanprodan]

This PR adds a label to the ClusterIP services and primary deployment metadata at bootstrap time. The label name is deduced from -selector-labels command flag, by default it will be app, name or app.kubernetes.io/name.

The label value is set to the object name, for example:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: podinfo-primary
  labels:
    app: podinfo-primary
---
apiVersion: v1
kind: Service
metadata:
  name: podinfo
  labels:
    app: podinfo
---
apiVersion: v1
kind: Service
metadata:
  name: podinfo-primary
  labels:
    app: podinfo-primary
---
apiVersion: v1
kind: Service
metadata:
  name: podinfo-canary
  labels:
    app: podinfo-canary

Ref: #329