overlay: Settings: Enable Smooth Display setting

lynx has peak refresh rate higher than
60 Hz, so allow users to toggle high-refresh rate like on stock.

Change-Id: I7fcbb905b61575de8c5e9d9a935463932551fb6a

overlay-lineage/packages/apps/Settings/res/values/config.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2021 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<resources>
+    <!-- Whether to show Smooth Display feature in Settings Options -->
+    <bool name="config_show_smooth_display">true</bool>
+</resources>