Create aconfig flag for desktop windowing

Bug: 304778354
Test: m
Change-Id: Ia911610ebfa232e942c08296db6b368642aaa34b
diff --git a/libs/WindowManager/Shell/aconfig/multitasking.aconfig b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
index 835ab93..7c0d0e3 100644
--- a/libs/WindowManager/Shell/aconfig/multitasking.aconfig
+++ b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
@@ -12,4 +12,11 @@
     namespace: "multitasking"
     description: "Enables the ability to create and save app pairs to the Home screen"
     bug: "274835596"
-}
\ No newline at end of file
+}
+
+flag {
+    name: "desktop_windowing"
+    namespace: "multitasking"
+    description: "Enables desktop windowing"
+    bug: "304778354"
+}