sm8450-common: overlay: Remove backup calling strings

AOSP killed them in [1].

[1]: https://github.com/LineageOS/android_packages_apps_Settings/commit/30b81d637e516bfaf262b1cc0a1c7df82613dc0b

Change-Id: Ie1d5d5ac76425cf49b834e6f578f6a6bde640d4e

overlay/SettingsResCommon/res/values/strings.xml

@@ -1,15 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-     Copyright (C) 2024 The LineageOS Project
-     SPDX-License-Identifier: Apache-2.0
--->
-<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
-    <!-- Mobile network settings screen, title of Backup calling setting.  [CHAR LIMIT=NONE] -->
-    <string name="backup_calling_settings_title">Voice Over Cellular Internet</string>
-
-    <!-- Backup calling summary.  [CHAR LIMIT=100] -->
-    <string name="backup_calling_setting_summary">"Extended voice coverage over cellular internet.\nDisclaimer: Charges associated with data plan usage may ensue"</string>
-
-    <!-- List of synonyms for the cross SIM calling titles, used to match in settings search [CHAR LIMIT=NONE] -->
-    <string name="keywords_backup_calling">Voice Over Cellular Internet</string>
-</resources>