Added check and save encryption settings

lib/screens/settings/encryption/config_error_modal.dart

@@ -0,0 +1,25 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+class EncryptionErrorModal extends StatelessWidget {
+  final String error;
+
+  const EncryptionErrorModal({
+    Key? key,
+    required this.error,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      title: Text(AppLocalizations.of(context)!.configError),
+      content: Text(error),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.pop(context), 
+          child: Text(AppLocalizations.of(context)!.close)
+        )
+      ],
+    );
+  }
+}