Showing a toast when changing wallaper is disabled

Bug: 27940102
Change-Id: I373093d9b85dca356aaa8798931d5315981fd74c
(cherry picked from commit 2afb636180fbc6832274aab1f8ac6e5407ae191a)
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 50b3d49..4e379a1 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -2735,6 +2735,11 @@
      * on the home screen.
      */
     protected void onClickWallpaperPicker(View v) {
+        if (!Utilities.isWallapaperAllowed(this)) {
+            Toast.makeText(this, R.string.msg_disabled_by_admin, Toast.LENGTH_SHORT).show();
+            return;
+        }
+
         if (LOGD) Log.d(TAG, "onClickWallpaperPicker");
         int pageScroll = mWorkspace.getScrollForPage(mWorkspace.getPageNearestToCenterOfScreen());
         float offset = mWorkspace.mWallpaperOffset.wallpaperOffsetForScroll(pageScroll);