Provide a way to set overrideHonorTimestamps to false in User Workload Monitoring

1. Proposed title of this feature request

Provide a way to set overrideHonorTimestamps to false in User Workload Monitoring

2. What is the nature and description of the request?

Right now, User Workload Monitoring (Prometheus) hardcodes overrideHonorTimestamps to "true". They would like this to be configurable. See here for a list of options that are currently configurable: https://docs.openshift.com/container-platform/4.14/monitoring/config-map-reference-for-the-cluster-monitoring-operator.html#prometheusrestrictedconfig

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

Their exporter sets its own timestamps, they don't want Prometheus overriding them.

4. List any affected packages or components.

Cluster Monitoring Operator