Launcher3: fix LauncherPreviewRenderer with qsb enable config

there is no activity in this context

Change-Id: I5f22f51935c94710e7f791a5dbbfb842a2fca3de
diff --git a/src/com/android/launcher3/qsb/QsbContainerView.java b/src/com/android/launcher3/qsb/QsbContainerView.java
index 5415a9b..ac20d13 100644
--- a/src/com/android/launcher3/qsb/QsbContainerView.java
+++ b/src/com/android/launcher3/qsb/QsbContainerView.java
@@ -281,19 +281,14 @@
         }
 
         private void rebindFragment() {
-            // Exit if the embedded qsb is disabled
-            if (!isQsbEnabled()) {
-                return;
-            }
-
-            if (mWrapper != null && getContext() != null) {
+            if (mWrapper != null && getContext() != null && isQsbEnabled()) {
                 mWrapper.removeAllViews();
                 mWrapper.addView(createQsb(mWrapper));
             }
         }
 
-        public boolean isQsbEnabled() {
-            return Utilities.showQsbWidget(getActivity())
+        private boolean isQsbEnabled() {
+            return Utilities.showQsbWidget(getContext())
                     && !SHOULD_SHOW_FIRST_PAGE_WIDGET;
         }