fix issue with universal output short form clobbering the dump option (#7894)

Author: scbedd

tools/test-proxy/Azure.Sdk.Tools.TestProxy/CommandOptions/OptionsGenerator.cs

@@ -53,7 +53,7 @@ public static RootCommand GenerateCommandLineOptions(Func<DefaultOptions, Task>
                 name: "--universalOutput",
                 description: "Flag; Redirect all logs to stdout, including what would normally be showing up on stderr.",
                 getDefaultValue: () => false);
-            dumpOption.AddAlias("-u");
+            universalOption.AddAlias("-u");
 
 
             var collectedArgs = new Argument<string[]>("args")