[Toast] Disable decorator updates if background drawables are used.

These lines cause an NPE when using Toast after toggling the flag.

Bug: 268470113
Test: manual
Change-Id: I3b2b162cde37fe780580872e015672c0c9339e4f
diff --git a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
index c3d24f9..ef2a2da 100644
--- a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
+++ b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
@@ -439,9 +439,11 @@
             return;
         }
 
-        RecyclerView.ItemDecoration decoration = getMainAdapterProvider().getDecorator();
-        getSearchRecyclerView().removeItemDecoration(decoration);
-        getSearchRecyclerView().addItemDecoration(decoration);
+        if (!FeatureFlags.ENABLE_SEARCH_RESULT_BACKGROUND_DRAWABLES.get()) {
+            RecyclerView.ItemDecoration decoration = getMainAdapterProvider().getDecorator();
+            getSearchRecyclerView().removeItemDecoration(decoration);
+            getSearchRecyclerView().addItemDecoration(decoration);
+        }
 
         // replaceAppsRVcontainer() needs to use both mUsingTabs value to remove the old view AND
         // showTabs value to create new view. Hence the mUsingTabs new value assignment MUST happen