Fetch the wallpaper category from the server instead of cache when launching the app(activity). am: ab03e09b13

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/12660783

Change-Id: I473c26ec37e3c4307c090c85bc70c87f7e751b57
diff --git a/src/com/android/customization/picker/CustomizationPickerActivity.java b/src/com/android/customization/picker/CustomizationPickerActivity.java
index 86845fc..786bebd 100644
--- a/src/com/android/customization/picker/CustomizationPickerActivity.java
+++ b/src/com/android/customization/picker/CustomizationPickerActivity.java
@@ -124,6 +124,8 @@
             return;
         }
 
+        mDelegate.getCategoryProvider().resetIfNeeded();
+
         setContentView(R.layout.activity_customization_picker_main);
         setUpBottomNavView();
         mBottomActionBar = findViewById(R.id.bottom_actionbar);