Invalid memory metric name issue

[mabdh]

Describe the bug
There is a warning when running entropy with dash in the app name

data-entropy-app-b7b7665-qxxl8 app 2023/09/04 06:17:31 Failed to export to Prometheus: cannot register the collector: descriptor Desc{fqName: "data-entropy_process_gc_sys", help: "Bytes of memory in garbage collection metadatas", constLabels: {}, variableLabels: []} is invalid: "data-entropy_process_gc_sys" is not a valid metric name

To Reproduce
Steps to reproduce the behavior:

1. Use dash in the app name
2. Run entropy

Expected behavior
No warning should be thrown and name should be valid