[bazel] combine finagle-thrift definitions
[bazel] combine finagle-thrift definitions

Follow up for D588333, so bazel won't create conflicting targets internally.

JIRA Issues: DPB-13038

Differential Revision: https://phabricator.twitter.biz/D589121

twitter/finagle,twitter/finagle,twitter/finagle,twitter/finagle,twitter/finagle