Underlying software defaults not always set on river types.

[erikbaranowski]

Scenario: A default is documented and being used by the underlying software but never set on a river type

For example, otelcol.receiver.opencensus > tls > min_version default "TLS 1.2"

Proposal: Set the default value documented in the flow component docs on the river type. This will have at least 2 benefits

1. We can see the default value in the Flow Graph UI
2. If the underlying software default changes and we miss it our documentation will still match agent functionality rather than quietly getting out of sync

[mattdurham]

I wonder if we could automate calling the API and comparing the API response to the running config to point out differences.