RTT bugfixes, part 5

* Add a new API to allow Telecom to inform ConnectionServices when the
RTT text stream changes
* No longer set the RTT property from ConnectionService. Client apps
should be setting properties themselves.
* Add Dialer-side RTT property in order to remove the dependence on
checking the RTT streams, which have a complex lifecycle

Bug: 72951201
Bug: 72648661
Test: manual, with real RTT calls and Dialer's SimulatorConnection, also
cts
Change-Id: Ic4c7d883d2dc6baf8e8c0eaa4df58d7de8762b9e
Merged-In: Ic4c7d883d2dc6baf8e8c0eaa4df58d7de8762b9e
diff --git a/telecomm/java/android/telecom/ConnectionService.java b/telecomm/java/android/telecom/ConnectionService.java
index 46d6b42..593e12b 100644
--- a/telecomm/java/android/telecom/ConnectionService.java
+++ b/telecomm/java/android/telecom/ConnectionService.java
@@ -143,6 +143,7 @@
     private static final String SESSION_HANDOVER_COMPLETE = "CS.hC";
     private static final String SESSION_EXTRAS_CHANGED = "CS.oEC";
     private static final String SESSION_START_RTT = "CS.+RTT";
+    private static final String SESSION_UPDATE_RTT_PIPES = "CS.uRTT";
     private static final String SESSION_STOP_RTT = "CS.-RTT";
     private static final String SESSION_RTT_UPGRADE_RESPONSE = "CS.rTRUR";
     private static final String SESSION_HANDOVER_FAILED = "CS.haF";
@@ -1864,7 +1865,6 @@
         Log.d(this, "stopRtt(%s)", callId);
         if (mConnectionById.containsKey(callId)) {
             findConnectionForAction(callId, "stopRtt").onStopRtt();
-            findConnectionForAction(callId, "stopRtt").unsetRttProperty();
         } else if (mConferenceById.containsKey(callId)) {
             Log.w(this, "stopRtt called on a conference.");
         }