Scaling by the average number of requests per pod

[kzhou57]

Description

We are looking to introduce a HPA target according to the number of requests, we found some metrics from newrelic can tell us that, for example : newrelic.goldenmetrics.apm.application.throughput. But it's the total requests for the application, however we didn't figure out a way to add a target for the average number of requests per pod.

I think since there is a metrics for all pods, the metrics adaptor should provide an operator to divide it by number of pods, and use it in hpa.

Acceptance Criteria

Support the scenario of autoscaling by request counts per pod.

Describe Alternatives

A clear and concise description of any alternative solutions or features you've considered
Are there examples you could link us to?

Dependencies

Do any other teams or parts of the New Relic product need to be considered?
Some common areas: UI, collector, documentation

Additional context

What else should we know about this story that might not fit into the other categories?

Estimates

Please provide initial t-shirt size. S = 1-3 days, M = 3-5 days (1 week), L = 1-2 weeks (1 sprint)

For Maintainers Only or Hero Triaging this bug

Suggested Priority (P1,P2,P3,P4,P5):
Suggested T-Shirt size (S, M, L, XL, Unknown):

[workato-integration]

https://new-relic.atlassian.net/browse/NR-292982