Create flag for enabling layout tracing in SystemUI

Flag: ACONFIG enable_layout_tracing DISABLED
Bug: 315274804
Test: perfetto trace
Change-Id: I8626536a95b9e9febbe3744f53765f61cd6f4859
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index c52a89c..086ec24 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -204,6 +204,13 @@
 }
 
 flag {
+  name: "enable_layout_tracing"
+  namespace: "systemui"
+  description: "Enables detailed traversal slices during measure and layout in perfetto traces"
+  bug: "315274804"
+}
+
+flag {
    name: "quick_settings_visual_haptics_longpress"
    namespace: "systemui"
    description: "Enable special visual and haptic effects for quick settings tiles with long-press actions"