Bug: ServiceMonitor should use https instead of http

current `servicemonitor` resources without option scheme, it can only be used for insecure clusters, example like this.

```yaml
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
name: cockroachdb
spec:
endpoints:
- interval: 10s
path: /_status/vars
port: http
# without scheme: https
tlsConfig:
ca:
secret:
key: ca.crt
name: cockroachdb-node
cert:
secret:
key: tls.crt
name: cockroachdb-node
insecureSkipVerify: true
keySecret:
key: tls.key
name: cockroachdb-node
namespaceSelector:
any: true
selector:
matchLabels:
app.kubernetes.io/component: cockroachdb
app.kubernetes.io/instance: cockroachdb
app.kubernetes.io/name: cockroachdb
```

Jira issue: HELM-15

Search the Helm chart templates and rendered manifests for the ServiceMonitor endpoint configuration and its default scheme. Render the affected chart with the example TLS settings, then verify that the generated ServiceMonitor uses HTTPS and that existing endpoint options remain intact.

Written by the indexing model from the issue text.