Fix empty metric reports

[aphralG]

Proposed changes

Setting defaults for advanced metrics flags caused empty metric reports to be sent.

• Remove defaults from advanced metrics flags
• Reduce log level of "Error getting default network interface"
• Clean up comms.go
• Check if report is empty before metrics report is sent

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING document
• If applicable, I have added tests that prove my fix is effective or that my feature works
• If applicable, I have checked that any relevant tests pass after adding my changes
• I have updated any relevant documentation (README.md)

[dhurley]

Looks good. Just have 2 minor comments

[Dean-Coakley]

👏

[sanathkumarbs]

Thank you for fixing this!

[sanathkumarbs]

Likely should close #79 as we this PR.