Make the process exit with the correct exit code. (#617)

* Make the process exit with the correct exit code.

* Add Environment.Exit(Environment.ExitCode); to the different services.

---------

Co-authored-by: Sarah Oslund <sfoslund@microsoft.com>

Author: gustavoaca1997

src/Microsoft.Sbom.Tool/FormatValidationService.cs

@@ -58,6 +58,7 @@ public async Task StartAsync(CancellationToken cancellationToken)
         }
 
         hostApplicationLifetime.StopApplication();
+        Environment.Exit(Environment.ExitCode);
     }
 
     public Task StopAsync(CancellationToken cancellationToken)

src/Microsoft.Sbom.Tool/GenerationService.cs

@@ -50,6 +50,7 @@ public async Task StartAsync(CancellationToken cancellationToken)
         }
 
         hostApplicationLifetime.StopApplication();
+        Environment.Exit(Environment.ExitCode);
     }
 
     public Task StopAsync(CancellationToken cancellationToken)

src/Microsoft.Sbom.Tool/RedactService.cs

@@ -43,6 +43,7 @@ public async Task StartAsync(CancellationToken cancellationToken)
         }
 
         hostApplicationLifetime.StopApplication();
+        Environment.Exit(Environment.ExitCode);
     }
 
     public Task StopAsync(CancellationToken cancellationToken)

src/Microsoft.Sbom.Tool/ValidationService.cs

@@ -60,6 +60,7 @@ public async Task StartAsync(CancellationToken cancellationToken)
         }
 
         hostApplicationLifetime.StopApplication();
+        Environment.Exit(Environment.ExitCode);
     }
 
     public Task StopAsync(CancellationToken cancellationToken)