fix(loki-mixin): Use valid RFC 1123 object names

[adinhodovic]

What this PR does / why we need it:

Fixes the loki-mixin to use valid object names. Getting issues when applying this through ArgoCD.

Which issue(s) this PR fixes:

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
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[trevorwhitney]

Would you mind filing an issue with an example of how this is breaking in ArgoCD for you, and maybe pointing to relevant section in the RFC 1123 spec? I wasn't aware in naming conventions in RFC 1123 beyond hostnames. I'm not necessarily against this change, just want to make sure I understand the motivation. Thanks!

[adinhodovic]

Would you mind filing an issue with an example of how this is breaking in ArgoCD for you, and maybe pointing to relevant section in the RFC 1123 spec? I wasn't aware in naming conventions in RFC 1123 beyond hostnames. I'm not necessarily against this change, just want to make sure I understand the motivation. Thanks!

These files become k8s configmaps and u cant have underscores in those.