Proper shutdown mechanism

[nanwng]

We were seeing lots of test timeout issues on macOS Ventura machines. It turned out that there's some shutdown error for simulators causing hanging bp processes. See below log for example:

{24164} 20230825.132813 [  ERROR ] (BP-1) Timeout: [Attempt 1] Create Simulator
{24164} 20230825.132813 [  ERROR ] (BP-1) The operation couldn’t be completed. (org.linkedin.bluepill.ErrorDomain error -1.)
{24164} 20230825.132813 [  INFO  ] (BP-1) Relaunching the simulator due to a BAD STATE
{24164} 20230825.132813 [  INFO  ] (BP-1) [Attempt 1] Delete Simulator
{24164} 20230825.132813 [  INFO  ] (BP-1) Shutting down Simulator
{24164} 20230825.132859 [  INFO  ] (BP-1) Simulator 0F53DAFD-72C0-4B9C-8DA0-6975202DBB28 achieved the BOOTED state Booted
{24164} 20230825.132900 [  INFO  ] (BP-1) Completed: [Attempt 1] Delete Simulator 0F53DAFD-72C0-4B9C-8DA0-6975202DBB28
{24164} 20230825.132900 [  ERROR ] (BP-1) EndTimerFailure: EndTimer called without starting a timer for 'Simulator 0F53DAFD-72C0-4B9C-8DA0-6975202DBB28'
{24164} 20230825.132900 [  INFO  ] (BP-1) [Attempt 1] Create Simulator
{24164} 20230825.132900 [  INFO  ] (BP-1) Booting a simulator without launching Simulator app
{24164} 20230825.133118 [  ERROR ] (BP-1) Simulator 354C7BB2-724C-4BEE-A966-29CF01B867B9 failed to boot. State: Shutdown
{24164} 20230825.133118 [  ERROR ] (BP-1) Shutting down Simulator failed: Unable to shutdown device in current state: Shutdown
{24164} 20230825.133118 [  ERROR ] (BP-1) Completed: [Attempt 1] Create Simulator 354C7BB2-724C-4BEE-A966-29CF01B867B9
{24164} 20230825.133118 [  ERROR ] (BP-1) Unable to boot the Simulator.
{24164} 20230825.133118 [  INFO  ] (BP-1) [Attempt 1] Delete Simulator
{24164} 20230825.133118 [  INFO  ] (BP-1) Shutting down Simulator
{24164} 20230825.133118 [  ERROR ] (BP-1) Shutting down Simulator failed: Unable to shutdown device in current state: Shutdown
{24164} 20230825.133118 [  ERROR ] (BP-1) Completed: [Attempt 1] Delete Simulator 354C7BB2-724C-4BEE-A966-29CF01B867B9
{24164} 20230825.133118 [  ERROR ] (BP-1) Unable to shutdown device in current state: Shutdown
{24164} 20230825.133118 [  INFO  ] (BP-1) Attempt's Exit Status: BPExitStatusSimulatorCreationFailed, Bundle exit status: BPExitStatusSimulatorCreationFailed
{24164} 20230825.133118 [  INFO  ] (BP-1) Exit Status: BPExitStatusSimulatorCreationFailed
{24164} 20230825.133118 [  INFO  ] (BP-1) Failure Tolerance: 1
{24164} 20230825.133118 [  INFO  ] (BP-1) Retry count: 1
{24164} 20230825.133118 [  INFO  ] (BP-1) Recovering from tooling problem

Fixing this by not calling the private shutdown api when the simulator is already in the shutdown state.