Place InputMethod after DockedDivider in window list.

We need to ensure that the InputMethod ends up
after the docked divider so it will have a higher
Z-order for input.

Bug: 28184654
Change-Id: Ifbe943312a82a79e850f106cc906f3749737710d
diff --git a/services/core/java/com/android/server/wm/DockedStackDividerController.java b/services/core/java/com/android/server/wm/DockedStackDividerController.java
index 0039c0a..b90d0d1 100644
--- a/services/core/java/com/android/server/wm/DockedStackDividerController.java
+++ b/services/core/java/com/android/server/wm/DockedStackDividerController.java
@@ -663,4 +663,8 @@
     public String toShortString() {
         return TAG;
     }
-}
\ No newline at end of file
+
+    WindowState getWindow() {
+        return mWindow;
+    }
+}