Move RTT system setting to Settings.Secure

Bug: 76449217
Test: manual
Change-Id: I85620d5b834aa7e04579212f3fd5cf6c0498b570
diff --git a/core/proto/android/providers/settings/secure.proto b/core/proto/android/providers/settings/secure.proto
index 593747d..3de8c39 100644
--- a/core/proto/android/providers/settings/secure.proto
+++ b/core/proto/android/providers/settings/secure.proto
@@ -340,6 +340,11 @@
     }
     optional Rotation rotation = 46;
 
+    // User-selected RTT mode. When on, outgoing and incoming calls will be
+    // answered as RTT calls when supported by the device and carrier. Boolean
+    // value.
+    optional SettingProto rtt_calling_mode = 69 [ (android.privacy).dest = DEST_AUTOMATIC ];
+
     message Screensaver {
         option (android.msg_privacy).dest = DEST_EXPLICIT;
 
@@ -474,5 +479,5 @@
 
     // Please insert fields in alphabetical order and group them into messages
     // if possible (to avoid reaching the method limit).
-    // Next tag = 69;
+    // Next tag = 70;
 }