Correct AWS STS Version 2 Location

The AWS STS library for Version 2 is included in nifi-aws-processors, but not in nifi-aws-service-api. The STS library needs to be in the same ClassLoader as the AWS Auth library for runtime credential loading. Version 1 of the STS library is already included in nifi-aws-service-api and corresponding NAR, which allows S3 Processors to work with STS. Other AWS Processors using SDK Version 2 need the STS library moved in order to work with this credentials strategy.