Enable onStopServing using THRIFT_FLAG
Enable onStopServing using THRIFT_FLAG

Reviewed By: ycking21

Differential Revision: D32638650

fbshipit-source-id: 8cea5d7a4ba03721f774c366233ef55b5b53dcea

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift