Always remember the last touch mode state when touch mode changes.

Do not just rely on getting an onWindowFocusChanged() event. There are cases
where we might not get it (view removed from the window for instance.)
diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java
index fd6af05..2f96aef 100644
--- a/core/java/android/widget/AbsListView.java
+++ b/core/java/android/widget/AbsListView.java
@@ -1953,6 +1953,7 @@
                 }
             }
         }
+        mLastTouchMode = isInTouchMode ? TOUCH_MODE_ON : TOUCH_MODE_OFF;
     }
 
     @Override