Skip adding namespaces if module doesn't need `ThemeModule`.

Resolve #19254

framework/src/Volo.Abp.Cli.Core/Volo/Abp/Cli/ProjectBuilding/Building/Steps/ChangeThemeStep.cs

@@ -37,9 +37,9 @@ public class ChangeThemeStep : ProjectBuildPipelineStep
     {
         var defaultThemeName = context.BuildArgs.TemplateName is AppTemplate.TemplateName or AppNoLayersTemplate.TemplateName
             ? LeptonXLite : LeptonX;
-        
+
         new RemoveFilesStep($"/Themes/{defaultThemeName}").Execute(context);
-        
+
         ChangeThemeToBasicForMvcProjects(context, defaultThemeName);
         ChangeThemeToBasicForBlazorProjects(context, defaultThemeName);
         ChangeThemeToBasicForBlazorServerProjects(context, defaultThemeName);
@@ -622,6 +622,11 @@ public class ChangeThemeStep : ProjectBuildPipelineStep
             return;
         }
 
+        if (!file.Content.Contains("ThemeModule"))
+        {
+            return;
+        }
+
         file.NormalizeLineEndings();
 
         var lines = file.GetLines().ToList();
@@ -630,7 +635,7 @@ public class ChangeThemeStep : ProjectBuildPipelineStep
         {
             lines.AddFirst(@namespace);
         }
-        
+
         file.SetLines(lines);
     }
 
@@ -641,7 +646,7 @@ public class ChangeThemeStep : ProjectBuildPipelineStep
             ".Web", ".AuthServer", ".Web.Public", ".Web.Public.Host",
             "" //for app-nolayers-mvc
         };
-        
+
         if(!context.Symbols.Contains("tiered"))
         {
             projectNames.Add(".HttpApi.Host");
@@ -716,7 +721,7 @@ public class ChangeThemeStep : ProjectBuildPipelineStep
                 context,
                 $"_Host.cshtml",
                 $"{defaultThemeName}Theme.Components",
-                "BasicTheme.Themes.Basic" 
+                "BasicTheme.Themes.Basic"
             );
 
             ReplaceAllKeywords(