ISSUE-2244: TLS support for Metrics API

[sijie]

Original Issue: apache#2244

---

FEATURE REQUEST

1. Please describe the feature you are requesting.
   I would like to be able to grab metrics from the metrics API using https rather than on standard http.

2. Indicate the importance of this issue to you (blocker, must-have, should-have, nice-to-have).
   Are you currently using any workarounds to address this issue? Currently I have to file an exception to our security team to use this endpoint without being secured.

3. Provide any additional detail on your proposed use case for this feature.