Enable SMS short code patterns to be updated from secure settings.

The premium SMS short code detector loads patterns from an XML resource
by default (frameworks/base/core/res/res/xml/sms_short_codes.xml).
Add support for updated patterns to be loaded on a per-country basis
from a secure setting named "sms_short_codes_" + the country code.
Updated patterns can be pushed to Google devices via Gservices.

Bug: 5513975
Change-Id: Ibfc0be4f12227ba45c28396ec7cdbc307442af81
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index ea3cab4..4c86d9c 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -4266,6 +4266,13 @@
                 "contacts_preauth_uri_expiration";
 
         /**
+         * Prefix for SMS short code regex patterns (country code is appended).
+         * @see com.android.internal.telephony.SmsUsageMonitor
+         * @hide
+         */
+        public static final String SMS_SHORT_CODES_PREFIX = "sms_short_codes_";
+
+        /**
          * This are the settings to be backed up.
          *
          * NOTE: Settings are backed up and restored in the order they appear