Treat the mdn as an additional voicemail number

Use carrier config to specify whether the carrier treats the mdn as an
additonal voicemail number.

Change-Id: I7192a3505da87d6b50a100e041d2b502cf37e113
Fix: 29145323
Test: build and flash on device
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 1f06283..500b4fd 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -73,6 +73,15 @@
             KEY_IGNORE_SIM_NETWORK_LOCKED_EVENTS_BOOL = "ignore_sim_network_locked_events_bool";
 
     /**
+     * When checking if a given number is the voicemail number, if this flag is true
+     * then in addition to comparing the given number to the voicemail number, we also compare it
+     * to the mdn. If this flag is false, the given number is only compared to the voicemail number.
+     * By default this value is false.
+     */
+    public static final String KEY_MDN_IS_ADDITIONAL_VOICEMAIL_NUMBER_BOOL =
+            "mdn_is_additional_voicemail_number_bool";
+
+    /**
      * Flag indicating whether the Phone app should provide a "Dismiss" button on the SIM network
      * unlock screen. The default value is true. If set to false, there will be *no way* to dismiss
      * the SIM network unlock screen if you don't enter the correct unlock code. (One important
@@ -1143,6 +1152,7 @@
 
         sDefaults.putBoolean(KEY_CARRIER_VOLTE_PROVISIONED_BOOL, false);
         sDefaults.putBoolean(KEY_IGNORE_SIM_NETWORK_LOCKED_EVENTS_BOOL, false);
+        sDefaults.putBoolean(KEY_MDN_IS_ADDITIONAL_VOICEMAIL_NUMBER_BOOL, false);
         sDefaults.putBoolean(KEY_OPERATOR_SELECTION_EXPAND_BOOL, true);
         sDefaults.putBoolean(KEY_PREFER_2G_BOOL, true);
         sDefaults.putBoolean(KEY_SHOW_APN_SETTING_CDMA_BOOL, false);