New carrier config enhanced_4g_lte_title_variant_int

Using KEY_ENHANCED_4G_LTE_TITLE_VARIANT_INT for customizing the title of
Enhanced 4G LTE Mode settings

Bug: 112676117
Test: Manual test, setting config to 0, 1, 2, 3 and -1 to change the index for
verifying different variant title of Enhanced 4G LTE Mode settings.

Change-Id: I614bb393c42c955c8ebac89d590c0c814bf43369
diff --git a/res/values/strings.xml b/res/values/strings.xml
index c7c4e2b..f61e69e 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -519,7 +519,15 @@
     <!-- Mobile network 4G title [CHAR LIMIT=30] -->
     <string name="enhanced_4g_lte_mode_title">Enhanced 4G LTE Mode</string>
     <!-- Carrier variant of Enhaced 4G LTE Mode title.  [CHAR LIMIT=50] -->
-    <string name="enhanced_4g_lte_mode_title_variant">Advanced Calling</string>
+    <string-array name="enhanced_4g_lte_mode_title_variant">
+        <!-- 0: Default -->
+        <item>@string/enhanced_4g_lte_mode_title</item>
+        <!-- 1: Verizon -->
+        <item>Advanced Calling</item>
+        <!-- 2: O2 UK -->
+        <item>4G Calling</item>
+    </string-array>
+
     <!-- Mobile network 4G summary [CHAR LIMIT=80] -->
     <string name="enhanced_4g_lte_mode_summary">Use LTE services to improve voice and other communications (recommended)</string>