Support VIRTUAL flag in keyboard layouts.

This flag is used to provide haptic feedback for virtual hard keys.

Bug: 14319563
Change-Id: Ia0ca1acc8cfa00a42d1c04d279dfa59c6cc00f4d
diff --git a/include/input/InputEventLabels.h b/include/input/InputEventLabels.h
index 36be4fc..1d67edf 100644
--- a/include/input/InputEventLabels.h
+++ b/include/input/InputEventLabels.h
@@ -340,6 +340,7 @@
 };
 
 static const InputEventLabel FLAGS[] = {
+    DEFINE_FLAG(VIRTUAL),
     DEFINE_FLAG(FUNCTION),
 
     { NULL, 0 }