Fixing issues in Launcher

- Now ending choice mode if a selected application is removed
- Only updating apps in the customization drawer if the applications change
- Adding null check when determining scrolling in PagedView

Change-Id: I0b23d1383649626dc012bd70a5e8087885b77c17
diff --git a/src/com/android/launcher2/PagedView.java b/src/com/android/launcher2/PagedView.java
index 9739b15..c125696 100644
--- a/src/com/android/launcher2/PagedView.java
+++ b/src/com/android/launcher2/PagedView.java
@@ -755,7 +755,9 @@
                 // by a distant descendant, so use the mAllowLongPress flag to block
                 // everything
                 final View currentPage = getPageAt(mCurrentPage);
-                currentPage.cancelLongPress();
+                if (currentPage != null) {
+                    currentPage.cancelLongPress();
+                }
             }
         }
     }