Verify aws_kinesis_firehose source

[spencergilbert]

• Verify internal event processing metrics are tested via assert_X_compliance test helpers
• Update component_discarded_events_total to match the new instrumentation spec by adding reason to the emitted logs, and intentional to emitted logs and metrics
• Verify that the component correctly emits the correct error events per the component spec

[spencergilbert]

Source appears to only drop events when failing a send, otherwise we don't receive events at all.

[jszwedko]

@spencergilbert did you verify the error events too? That is, the ones that emit component_errors_total (or if any are missing).

[spencergilbert]

@spencergilbert did you verify the error events too? That is, the ones that emit component_errors_total (or if any are missing).

Yep, the two "custom" internal events that emit errors have all the properties from the spec 👍