Remove dependency to Apache HttpCore

[joain946]

Serverless Java Container version: 1.5.2

Implementations: Jersey

Framework version: Jersey 2.30.1

Frontend service: HTTP API

Deployment method: SAM

Scenario

I want to minimize the number of dependencies used by my Lambda. Apache HttpCore is used in four classes, three of these are only used for testing. The fourth class is the AwsHttpServletRequest which only instantiates one class from Apache HttpCore but never uses it: https://github.com/awslabs/aws-serverless-java-container/blob/4380cc05fb96ccc61f8a76ff6f6381bb3ab75260/aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsHttpServletRequest.java#L110

Expected behavior

I want to be able to exclude Apache HttpCode ("httpcomponents-core") in my pom file.

Actual behavior

The class is needed.

[deki]

Thanks for reporting this issue. For now I've removed the unused BasicHeaderValueParser and marked the dependency as optional in the pom.
In the future we could move AwsProxyRequestBuilder to a separate test-jar.