Create carrier settings menu

If config_carrier_settings_enable set true, show the menu, which is located in
Settings > More (under Wireless & Networks) > Mobile Networks > Carrier settings

Bug: 10706591
Change-Id: I50b008ac04763fda4b1a340b636bc03de76f257f
diff --git a/res/values/strings.xml b/res/values/strings.xml
index ad876fa..5da301d 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -614,6 +614,10 @@
     <!-- Preference title for launching an account manager page for prepaid LTE [CHAR LIMIT=30] -->
     <string name="cdma_lte_data_service">Set up data service</string>
 
+    <!-- A menu item in "Mobile network settings" that allows the user to update the phone
+         with mobile operator specific settings. [CHAR LIMIT=25] -->
+    <string name="carrier_settings_title">Carrier settings</string>
+
     <!-- FDN settings strings -->
     <!-- Call settings screen, setting option name -->
     <string name="fdn">Fixed Dialing Numbers</string>