Update attributes configs default values

[kaylareopelle]

The Ruby Agent is not yet in compliance with the default attributes.include and attributes.exclude values outlined in the Agent Attributes PORTED: Request Headers spec (Internal).

It also seems like we need to add an allow_all_headers to meet the full spec requirements.

Original discussion (Internal)

T-Shirt size

[workato-integration]

https://issues.newrelic.com/browse/NEWRELIC-3463

[fallwith]

The "all headers" part may be related to #1029

[fallwith]

The allow_all_headers functionality went in with #2155.

For the include and exclude lists, there has been .NET agent work recently to specifically implement new excludes for use with request headers. But given that these lists are used for more than just request headers and given the non-request-header-specific agent specs that do indeed call for empty lists as we have now, we're hesitant to make any changes at this time that could impact existing customers unexpectedly.

As customer requests and large scale specs vs. implementation audits continue, we can revisit later - possibly with a major agent version bump.