Automatically whitelist all idl jar dependencies

There's a commit in the log:

e1fc595b4 "automatically whitelist all idl jar dependencies"
RB_ID=190149

Maybe I misinterpreted the intention - but it doesn't actually whitelist all IDL files. It only filters non-IDL-files from transitive dependencies.

This pull request will add support for automatically whitelisting artifacts with an "idl" classifier.