Reduce apiserver metric cardinality (#2531)

* Reduce apiserver metric cardinality

Current releases of Kubernetes added new metrics that also have the same
excessive bucket cardinality. Remove the extra buckets from these
metrics.
* `apiserver_request_sli_duration_seconds_bucket`
* `etcd_request_duration_seconds_bucket`

Also reduce the cardinality of apiserver byte histogram metrics.
* `apiserver_request_bdy_size_bytes_bucket`

This reduces API server metrics in our configuration by about 25%.

Signed-off-by: SuperQ <superq@gmail.com>

* Apply suggestions from code review

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Signed-off-by: SuperQ <superq@gmail.com>
Co-authored-by: Simon Pasquier <spasquie@redhat.com>