Dimensions of custom metrics are prefixed with prop_

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All

#### Question
Dimensions of custom metrics are prefixed with `prop_` which is similar to traces, et al.

However, with dimensions this is not ideal since they are using in alerts, reports, dashboards and more - Is there a way where we can override this at our own risk of having duplicate keys?

The issue identifies custom metric dimensions and the `prop_` prefix, but names no files, tests, or entry points. Start by locating the host code that assigns prefixes to custom metric dimensions, then determine how an opt-out would affect alerts, reports, dashboards, and duplicate keys.

Written by the indexing model from the issue text.