serverless: Investigate a reported requirement that the NR Ruby layer be the first layer

[fallwith]

It has been reported that the New Relic layer must be the first one that is merged in, or else things will not function properly and the blue banner will persist. The blue banner refers to the text based "not yet instrumented" type notification at the top of the New Relic web UI for displaying a given Lambda function if New Relic has learned of the function through CloudWatch but not the New Relic Lambda extension.

We had previously thought that not only will the New Relic layer be okay coming second or later, but that it was actually a good thing for it to come as late as possible so that all gems to be auto-instrumented would have had a chance to load and be visible to the New Relic Ruby agent. And we had previously thought that even if those gems were not seen, the blue banner would still disappear and the extension's data for the overall function performance would still reach New Relic without issue.

We should investigate the layer order requirements and then see if the requirements can either be relaxed or addressed with updated documentation.

[workato-integration]

https://new-relic.atlassian.net/browse/NR-270878