Fix focus issue when profile selected from nested menu entry (#15077)

Original bug report #15049
Relates to feature #1571

MenuFlyoutSubItem, when collapsing from profile selection, move focus
back to the titlebar.
An extra Closing event handler is needed to keep focus on the command
shell.

Closes #15049

(cherry picked from commit def3742)
Service-Card-Id: 89002014
Service-Version: 1.17

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -924,6 +924,10 @@ namespace winrt::TerminalApp::implementation
         newTabFlyout.Opening([this](auto&&, auto&&) {
             _FocusCurrentTab(true);
         });
+        // Necessary for fly-out sub items to get focus on a tab before collapsing. Related to #15049
+        newTabFlyout.Closing([this](auto&&, auto&&) {
+            _FocusCurrentTab(true);
+        });
         _newTabButton.Flyout(newTabFlyout);
     }