Add flag for layout transitions for Recent Apps in Taskbar.

Change-Id: Ie5c9b5c9373ac289054f1c7f330106004ddc3de4
Flag: com.android.launcher3.taskbar_recents_layout_transition
Bug: 343521765
Test: go/testedequals
diff --git a/aconfig/launcher.aconfig b/aconfig/launcher.aconfig
index ee7e975..878aa6e 100644
--- a/aconfig/launcher.aconfig
+++ b/aconfig/launcher.aconfig
@@ -519,4 +519,11 @@
   namespace: "launcher"
   description: "Enable MSDL feedback for Launcher interactions"
   bug: "377496684"
+}
+
+flag {
+    name: "taskbar_recents_layout_transition"
+    namespace: "launcher"
+    description: "Enable Taskbar LayoutTransition for Recent Apps"
+    bug: "343521765"
 }
\ No newline at end of file