ClangFormat: Fix preview updating

Fixed the behavior when the preview does not update when the Override
checkbox was not enabled initially. Currently, the preview is updating
when Override the checkbox is enabled.

Fixes: QTCREATORBUG-29043
Change-Id: I8a2a6f3cd5890b66d4bffd0c84aeafb5a29fba48
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/clangformat/clangformatutils.cpp

@@ -215,9 +215,10 @@ bool getCurrentOverriddenSettings(const Utils::FilePath &filePath)
     const ProjectExplorer::Project *project = ProjectExplorer::SessionManager::projectForFile(
         filePath);
 
-    return getProjectUseGlobalSettings(project)
-               ? ClangFormatSettings::instance().overrideDefaultFile()
-               : getProjectOverriddenSettings(project);
+    return getProjectUseGlobalSettings(project) ? !TextEditor::TextEditorSettings::codeStyle("Cpp")
+                                                       ->currentPreferences()
+                                                       ->isTemporarilyReadOnly()
+                                                : getProjectOverriddenSettings(project);
 }
 
 ClangFormatSettings::Mode getProjectIndentationOrFormattingSettings(