Fixing issue where you couldn't set null RemoteViews for a widget

-> As noted here: http://code.google.com/p/android/issues/detail?id=35014

Change-Id: Id5d1c47b6961d4b448453d8b16700801c0137f2b

Author: Adam Cohen

services/java/com/android/server/AppWidgetServiceImpl.java

@@ -817,7 +817,10 @@ public void updateAppWidgetIds(int[] appWidgetIds, RemoteViews views) {
             return;
         }
 
-        int bitmapMemoryUsage = views.estimateMemoryUsage();
+        int bitmapMemoryUsage = 0;
+        if (views != null) {
+            bitmapMemoryUsage = views.estimateMemoryUsage();
+        }
         if (bitmapMemoryUsage > mMaxWidgetBitmapMemory) {
             throw new IllegalArgumentException("RemoteViews for widget update exceeds maximum" +
                     " bitmap memory usage (used: " + bitmapMemoryUsage + ", max: " +