Proposed title of this feature request

LabelKeys enabled for Red Hat Managed LokiStack

What is the nature and description of the request?

Currently, it's possible to set `clusterlogforwarder.spec.outputs.loki.labelKeys` for when log forwarding to a Red Hat not Managed Loki.

This RFE is for asking to enable `labelKeys` also for the Red Hat Managed Loki.

Why does the customer need this? (List the business requirements)

With the default labelKeys, as using pipelines, every day is destroyed and created a big number of pods generating a big cardinality as it can be in the stream label `kubernetes_pod_name` what can lead to Loki performance issues as perfectly described in the Loki upstream documentation  [1] where it's said:

Note: If the set of labels has high cardinality, this can cause drastic performance issues with Loki. To prevent this from happening, reduce the number of unique label keys and values.

Having a better control of the labels in Loki will help to optimize and improve the performance of Loki. An example of an output of the Labels cardinality where the `kubernetes_pod_name`  shows a high cardinality in the last 12 hours:

Label Name                 Unique Values  Found In Streams
kubernetes_pod_name        7932           15620
kubernetes_container_name  236            15620
kubernetes_namespace_name  179            15620
kubernetes_host            26             15620
log_type                   1              15620 

List any affected packages or components.
LokiStack

 [1] https://vector.dev/docs/reference/configuration/sinks/loki/#labels