Investigate Enabling HorizontalPodAutoscaler Resource in Loki chart

The Loki chart comes with a couple of HorizontalPodAutoscaler resources and we've confirmed that Loki read pods don't require any extra configuration beyond the default config and setting strategy=scalable to support multiple replcas: https://repo1.dso.mil/big-bang/bigbang/-/blob/master/docs/understanding-bigbang/package-architecture/loki.md#high-availability

Test deploying Loki with this HorizontalPodAutoscaler enabled via read.autoscaling.enabled and see if any of the other autoscaling or read values need to be tuned or altered for better performance.

If no issues or other dependencies are required, enable this HorizontalPodAutoscaler for the package in BigBang so it is enabled by default for read pods.

• Deploy and test Loki with the read HorizontalPodAutoscaler resource enabled
• Document any caveats or recommendations in above linked package-architecture/loki.md#high-availability document
• Enable autoscaling value in BigBang pass-through values if no large caveats or recommendations are required