Proper ContextManager Shutdown
Proper ContextManager Shutdown

Summary: This will ensure that the process is fully terminated in the CM

Reviewed By: zeyadsalloum

Differential Revision: D20595180

fbshipit-source-id: 1bbab75e4dfa9a60bf629d359e7e942e39b4da4c

facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl