minor refactor

framework/src/Volo.Abp.Cli.Core/Volo/Abp/Cli/ProjectBuilding/Building/MobileApp.cs

@@ -17,9 +17,9 @@ namespace Volo.Abp.Cli.ProjectBuilding.Building
             {
                 case MobileApp.ReactNative:
                     return "react-native";
-                default:
-                    return null;
             }
+
+            throw new Exception("Mobile app folder name is not set!");
         }
     }
 }

framework/src/Volo.Abp.Cli.Core/Volo/Abp/Cli/ProjectBuilding/Templates/App/AppTemplateBase.cs

@@ -77,7 +77,7 @@ namespace Volo.Abp.Cli.ProjectBuilding.Templates.App
 
             if (context.BuildArgs.MobileApp != MobileApp.ReactNative)
             {
-                steps.Add(new RemoveFolderStep(MobileApp.ReactNative.GetFolderName()?.EnsureStartsWith('/')));
+                steps.Add(new RemoveFolderStep(MobileApp.ReactNative.GetFolderName().EnsureStartsWith('/')));
             }
         }