Unify on-the-fly docs settings with C++ (#74663)

src/VisualStudio/CSharp/Impl/Options/CSharpVisualStudioCopilotOptionsService.cs

@@ -42,7 +42,7 @@ internal sealed class CSharpVisualStudioCopilotOptionsService : ICopilotOptionsS
     private const string CopilotOptionNamePrefix = "Microsoft.VisualStudio.Conversations";
     private const string CopilotCodeAnalysisOptionName = "EnableCSharpCodeAnalysis";
     private const string CopilotRefineOptionName = "EnableCSharpRefineQuickActionSuggestion";
-    private const string CopilotOnTheFlyDocsOptionName = "EnableCSharpOnTheFlyDocs";
+    private const string CopilotOnTheFlyDocsOptionName = "EnableOnTheFlyDocs";
 
     private static readonly UIContext s_copilotHasLoadedUIContext = UIContext.FromUIContextGuid(new Guid(CopilotHasLoadedGuid));
     private static readonly UIContext s_gitHubAccountStatusDeterminedContext = UIContext.FromUIContextGuid(new Guid(GitHubAccountStatusDetermined));