Fix null exception of BottomActionBar#AccessibilityCallback

Please double check new changes after getting +2

Test: Manually
Fixes: 159794196
Change-Id: Ia4add15daf5ca1b04fbe885c6d78ce3019a39caa
diff --git a/src/com/android/wallpaper/widget/BottomActionBar.java b/src/com/android/wallpaper/widget/BottomActionBar.java
index 9b8fc73..c6dc61a 100644
--- a/src/com/android/wallpaper/widget/BottomActionBar.java
+++ b/src/com/android/wallpaper/widget/BottomActionBar.java
@@ -474,7 +474,7 @@
     }
 
     private void notifyAccessibilityCallback(int state) {
-        if (mAccessibilityCallback != null) {
+        if (mAccessibilityCallback == null) {
             return;
         }