Clean unbooted simulators
Clean unbooted simulators

Summary:
The `clean` operation fails when the target is not booted because it can't list nor uninstall apps.
These changes make `clean` check the status of the target and only execute the cleaning steps that
make sense in each state.

Reviewed By: c-ryan747

Differential Revision: D27675464

fbshipit-source-id: a96a767f7b6922bf7a8b9502e2f7c904485c95f0

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