Update pointer icon when View.setPointerIcon is called

Currently the updated pointer icon is only displayed after
the next mouse move.

Bug:27107871
Change-Id: Ieed57b07fe44699735179cf57968a9bb08981396
diff --git a/services/core/java/com/android/server/wm/Session.java b/services/core/java/com/android/server/wm/Session.java
index a8d974f..25de75a 100644
--- a/services/core/java/com/android/server/wm/Session.java
+++ b/services/core/java/com/android/server/wm/Session.java
@@ -528,6 +528,16 @@
         }
     }
 
+    @Override
+    public void updatePointerIcon(IWindow window) {
+        final long identity = Binder.clearCallingIdentity();
+        try {
+            mService.updatePointerIcon(window);
+        } finally {
+            Binder.restoreCallingIdentity(identity);
+        }
+    }
+
     void windowAddedLocked() {
         if (mSurfaceSession == null) {
             if (WindowManagerService.localLOGV) Slog.v(