Add aconfig flag for enable_split_contextual

Bug: 276361926
Test: Not needed
Change-Id: I9bdb64739cf0e360b881212ecfbb91569579b20e
diff --git a/libs/WindowManager/Shell/aconfig/multitasking.aconfig b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
index 7c0d0e3..51c71b1 100644
--- a/libs/WindowManager/Shell/aconfig/multitasking.aconfig
+++ b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
@@ -20,3 +20,10 @@
     description: "Enables desktop windowing"
     bug: "304778354"
 }
+
+flag {
+    name: "enable_split_contextual"
+    namespace: "multitasking"
+    description: "Enables invoking split contextually"
+    bug: "276361926"
+}