Extract APIGatewayProxyRequestEvent headers for context propagation

[cleverchuk]

Extract APIGatewayProxyRequestEvent headers for context propagation. This change is only added to aws-lambda-events-2.2 package because the aws-lambda-core instrumentation only applies to Lambdas that use custom events.

[cleverchuk]

@tylerbenson @laurit

[laurit]

@cleverchuk could you update the PR title, we use PR titles in changelog.

[tylerbenson]

An additional unit test might be nice. Not sure how much effort that would be though.

[laurit]

@cleverchuk could you see if it is possible to build a test similar to

opentelemetry-java-instrumentation/instrumentation/aws-lambda/aws-lambda-events-2.2/library/src/test/java/io/opentelemetry/instrumentation/awslambdaevents/v2_2/AwsLambdaApiGatewayWrapperTest.java

Line 65 in 780cdf4

void tracedWithHttpPropagation() {

that would test the functionality that you have implemented.

[cleverchuk]

@laurit @tylerbenson added a test. I don't understand entirely how the testing works though. However the test fails without the change, which I think is a good sign. This check kept failing so I removed it because I don't know how to get it to work.

equalTo(HttpAttributes.HTTP_RESPONSE_STATUS_CODE, 201L)

[laurit]

@laurit @tylerbenson added a test. I don't understand entirely how the testing works though. However the test fails without the change, which I think is a good sign. This check kept failing so I removed it because I don't know how to get it to work.

equalTo(HttpAttributes.HTTP_RESPONSE_STATUS_CODE, 201L)

Thanks, I added the http.response.status_code attribute.