Add carrier config keys for RTT-VT compat

Some carriers don't allow downgraded RTT calls to be upgraded to VT or
vice versa. Add carrier config keys to capture this behavior.

Bug: 175659924
Test: NA
Change-Id: I03916e1fab9abe58733c06f351b6846ddc29f337

2 files changed, 16 insertions, 0 deletions

diff --git a/core/api/current.txt b/core/api/current.txt
index b0d659a6caa0..b00d90f52929 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -39271,6 +39271,7 @@ package android.telephony {
     field public static final String KEY_RTT_SUPPORTED_FOR_VT_BOOL = "rtt_supported_for_vt_bool";
     field public static final String KEY_RTT_SUPPORTED_WHILE_ROAMING_BOOL = "rtt_supported_while_roaming_bool";
     field public static final String KEY_RTT_UPGRADE_SUPPORTED_BOOL = "rtt_upgrade_supported_bool";
+    field public static final String KEY_RTT_UPGRADE_SUPPORTED_FOR_DOWNGRADED_VT_CALL_BOOL = "rtt_upgrade_supported_for_downgraded_vt_call";
     field public static final String KEY_SHOW_4G_FOR_3G_DATA_ICON_BOOL = "show_4g_for_3g_data_icon_bool";
     field public static final String KEY_SHOW_4G_FOR_LTE_DATA_ICON_BOOL = "show_4g_for_lte_data_icon_bool";
     field public static final String KEY_SHOW_APN_SETTING_CDMA_BOOL = "show_apn_setting_cdma_bool";
@@ -39313,6 +39314,7 @@ package android.telephony {
     field public static final String KEY_VOICEMAIL_NOTIFICATION_PERSISTENT_BOOL = "voicemail_notification_persistent_bool";
     field public static final String KEY_VOICE_PRIVACY_DISABLE_UI_BOOL = "voice_privacy_disable_ui_bool";
     field public static final String KEY_VOLTE_REPLACEMENT_RAT_INT = "volte_replacement_rat_int";
+    field public static final String KEY_VT_UPGRADE_SUPPORTED_FOR_DOWNGRADED_RTT_CALL_BOOL = "vt_upgrade_supported_for_downgraded_rtt_call";
     field public static final String KEY_VVM_CELLULAR_DATA_REQUIRED_BOOL = "vvm_cellular_data_required_bool";
     field public static final String KEY_VVM_CLIENT_PREFIX_STRING = "vvm_client_prefix_string";
     field public static final String KEY_VVM_DESTINATION_NUMBER_STRING = "vvm_destination_number_string";
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 04e8f6345dee..9e01d0a3250d 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -2853,6 +2853,18 @@ public class CarrierConfigManager {
     public static final String KEY_RTT_SUPPORTED_FOR_VT_BOOL = "rtt_supported_for_vt_bool";
 
     /**
+     * Indicates if the carrier supports upgrading a call that was previously an RTT call to VT.
+     */
+    public static final String KEY_VT_UPGRADE_SUPPORTED_FOR_DOWNGRADED_RTT_CALL_BOOL =
+            "vt_upgrade_supported_for_downgraded_rtt_call";
+
+    /**
+     * Indicates if the carrier supports upgrading a call that was previously a VT call to RTT.
+     */
+    public static final String KEY_RTT_UPGRADE_SUPPORTED_FOR_DOWNGRADED_VT_CALL_BOOL =
+            "rtt_upgrade_supported_for_downgraded_vt_call";
+
+    /**
      * Indicates if the carrier supports upgrading a voice call to an RTT call during the call.
      */
     public static final String KEY_RTT_UPGRADE_SUPPORTED_BOOL = "rtt_upgrade_supported_bool";
@@ -4534,6 +4546,8 @@ public class CarrierConfigManager {
         sDefaults.putBoolean(KEY_TTY_SUPPORTED_BOOL, true);
         sDefaults.putBoolean(KEY_HIDE_TTY_HCO_VCO_WITH_RTT_BOOL, false);
         sDefaults.putBoolean(KEY_RTT_SUPPORTED_WHILE_ROAMING_BOOL, false);
+        sDefaults.putBoolean(KEY_RTT_UPGRADE_SUPPORTED_FOR_DOWNGRADED_VT_CALL_BOOL, true);
+        sDefaults.putBoolean(KEY_VT_UPGRADE_SUPPORTED_FOR_DOWNGRADED_RTT_CALL_BOOL, true);
         sDefaults.putBoolean(KEY_DISABLE_CHARGE_INDICATION_BOOL, false);
         sDefaults.putBoolean(KEY_SUPPORT_NO_REPLY_TIMER_FOR_CFNRY_BOOL, true);
         sDefaults.putStringArray(KEY_FEATURE_ACCESS_CODES_STRING_ARRAY, null);