fix spotbugs

Signed-off-by: alperozturk96 <alper_ozturk@proton.me>

Author: alperozturk96

app/src/main/java/com/nextcloud/client/preferences/AppPreferences.java

@@ -13,7 +13,6 @@
 import com.nextcloud.appReview.AppReviewShownModel;
 import com.nextcloud.client.jobs.LogEntry;
 import com.owncloud.android.datamodel.OCFile;
-import com.owncloud.android.ui.fragment.FileListLayoutManager;
 import com.owncloud.android.ui.fragment.FolderLayout;
 import com.owncloud.android.utils.FileSortOrder;
 
@@ -145,7 +144,7 @@ default void onDarkThemeModeChanged(DarkMode mode) {
      * @param layout FolderLayout which layout is being set
      * @param layoutName preference value
      */
-    void setFolderLayout(@Nullable FolderLayout layout, String layoutName);
+    void setFolderLayout(@NonNull FolderLayout layout, String layoutName);
 
     /**
      * Saves the path where the user selected to do the last upload of a file shared from other app.

app/src/main/java/com/nextcloud/client/preferences/AppPreferencesImpl.java

@@ -355,7 +355,7 @@ public String getFolderLayout(FolderLayout layout) {
     }
 
     @Override
-    public void setFolderLayout(FolderLayout layout, String layoutName) {
+    public void setFolderLayout(@NonNull FolderLayout layout, String layoutName) {
         if (layout instanceof FolderLayout.Child child) {
             setFolderPreference(context,
                                 userAccountManager.getUser(),