NullReferenceException when xharness tries to list device which is untrusted

[akoeplinger]

This happened in dotnet/runtime#95980 (comment) due to an untrusted device: dotnet/dnceng#1749

[07:14:22] dbug: Looking for available ios-device devices. Storing logs into list-ios-device-20231229_071422.log
[07:14:25] crit: System.NullReferenceException: Object reference not set to an instance of an object.
                    at Microsoft.DotNet.XHarness.iOS.Shared.Hardware.Device.get_Architecture() in /_/src/Microsoft.DotNet.XHarness.iOS.Shared/Hardware/Device.cs:line 100
                    at Microsoft.DotNet.XHarness.iOS.Shared.Hardware.Device.get_Supports64Bit() in /_/src/Microsoft.DotNet.XHarness.iOS.Shared/Hardware/Device.cs:line 82
                    at Microsoft.DotNet.XHarness.iOS.Shared.Hardware.HardwareDeviceLoader.<>c.<get_Connected64BitIOS>b__7_0(IHardwareDevice x) in /_/src/Microsoft.DotNet.XHarness.iOS.Shared/Hardware/HardwareDeviceLoader.cs:line 48
                    at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
                    at System.Linq.Enumerable.TryGetFirst[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
                    at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
                    at Microsoft.DotNet.XHarness.Apple.DeviceFinder.FindDevice(TestTargetOs target, String deviceName, ILog log, Boolean includeWirelessDevices, Boolean pairedDevicesOnly, CancellationToken cancellationToken) in /_/src/Microsoft.DotNet.XHarness.Apple/DeviceFinder.cs:line 87
                    at Microsoft.DotNet.XHarness.Apple.BaseOrchestrator.OrchestrateOperationInternal(TestTargetOs target, String deviceName, Boolean includeWirelessDevices, Boolean resetSimulator, Boolean enableLldb, GetAppBundleInfoFunc getAppBundle, ExecuteMacCatalystAppFunc executeMacCatalystApp, ExecuteAppFunc executeApp, CancellationToken cancellationToken) in /_/src/Microsoft.DotNet.XHarness.Apple/Orchestration/BaseOrchestrator.cs:line 215
                    at Microsoft.DotNet.XHarness.Apple.BaseOrchestrator.OrchestrateOperation(TestTargetOs target, String deviceName, Boolean includeWirelessDevices, Boolean resetSimulator, Boolean enableLldb, GetAppBundleInfoFunc getAppBundle, ExecuteMacCatalystAppFunc executeMacCatalystApp, ExecuteAppFunc executeApp, CancellationToken cancellationToken) in /_/src/Microsoft.DotNet.XHarness.Apple/Orchestration/BaseOrchestrator.cs:line 96
                    at Microsoft.DotNet.XHarness.Apple.RunOrchestrator.OrchestrateRun(GetAppBundleInfoFunc getAppBundleInfo, TestTargetOs target, String deviceName, TimeSpan timeout, TimeSpan launchTimeout, Int32 expectedExitCode, Boolean includeWirelessDevices, Boolean resetSimulator, Boolean enableLldb, Boolean signalAppEnd, Boolean waitForExit, IReadOnlyCollection`1 environmentalVariables, IEnumerable`1 passthroughArguments, CancellationToken cancellationToken) in /_/src/Microsoft.DotNet.XHarness.Apple/Orchestration/RunOrchestrator.cs:line 221
                    at Microsoft.DotNet.XHarness.CLI.Commands.Apple.AppleAppCommand`1.Invoke(ILogger logger) in /_/src/Microsoft.DotNet.XHarness.CLI/Commands/Apple/AppleAppCommand.cs:line 68
                    at Microsoft.DotNet.XHarness.CLI.Commands.XHarnessCommand`1.Invoke(IEnumerable`1 arguments) in /_/src/Microsoft.DotNet.XHarness.CLI/Commands/XHarnessCommand.cs:line 145
XHarness exit code: 71 (GENERAL_FAILURE)

If I look at list-ios-device-20231229_071422.log then it shows this:

[07:14:24.2266790] Xamarin.Hosting: Device discovery started
[07:14:24.2485540] Xamarin.Hosting: Device discovery event: Connected (00008020-00093D840A7B002E)
[07:14:24.2601530] Xamarin.Hosting: Connected to DNCENGOSX-010 (00008020-00093D840A7B002E) in 00:00:00.0040882
[07:14:24.2816810] Failed to start session on DNCENGOSX-010: Invalid Host ID Error (error: 0xe800001c). Please check that the device is trusting the machine it's connected to, and then unplug and reconnect the device.
[07:14:24.2960570] 2023-12-29 07:14:24.295 mlaunch[26957:272444] DVTCoreDeviceEnabledState: DVTCoreDeviceEnabledState_Disabled set via user default (DVTEnableCoreDevice=(null))
[07:14:24.6122930] Xamarin.Hosting: Connecting to 'DNCENGOSX-010', token is 0x7fb948d32740
[07:14:24.7831790] Xamarin.Hosting: Device discovery event: Unsubscribed ()
[07:14:24.7832150] Xamarin.Hosting: Device discovery event: Unsubscribed ()
[07:14:24.7835130] Xamarin.Hosting: Device discovery stopped
[07:14:25.0600130] Xamarin.Hosting: Connected to 'DNCENGOSX-010'
[07:14:25.3091860] Process mlaunch exited with 0
[07:14:25.3157670] Found 1 devices
[07:14:25.3247410] Found following devices: 'DNCENGOSX-010'

xharness should handle this case.