Fix issue with extra empty screen left over after widget add cancel (issue 10865959)

Change-Id: Iee72fe1b296e81a5f2d04f6edcbf9cac19aff992
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 278b13c..ee13f29 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -736,6 +736,7 @@
                 Log.e(TAG, "Error: appWidgetId (EXTRA_APPWIDGET_ID) was not returned from the \\" +
                         "widget configuration activity.");
                 completeTwoStageWidgetDrop(RESULT_CANCELED, appWidgetId);
+                mWorkspace.stripEmptyScreens();
             } else {
                 completeTwoStageWidgetDrop(resultCode, appWidgetId);
             }
@@ -760,6 +761,8 @@
             } else {
                 delayExitSpringLoadedMode = completeAdd(args);
             }
+        } else if (resultCode == RESULT_CANCELED) {
+            mWorkspace.stripEmptyScreens();
         }
         mDragLayer.clearAnimatedView();
         // Exit spring loaded mode if necessary after cancelling the configuration of a widget