Passing configuration function to nodejs lambda instrumentation package

[sgracias1]

Describe the bug
The lambda instrumentation layer provides a way to pass a configuration function to @opentelemetry/instrumentation-aws-lambda (link). However it is not clear how the user would provide such a function.
I have tried placing such a function definition at the root of my lambda function but that doesn't seem to work, the only place the definition was picked up was if the wrapper file itself was modified.

What did you expect to see?
Allow user to pass the configuration function to the lambda instrumentation package
Is providing the configuration function by the user currently supported, if so how would a user provide this function

What version of collector/language SDK version did you use?
nodejs layer 0.2.0

What language layer did you use?
Nodejs

Additional context
Add any other context about the problem here.

[timothymathison]

Is this a duplicate of #232 ?