Track conference start in system elapsed time.

This is important so that Telecom can track the duration of the call,
which is tracked using wall clock time.

Test: Manual, unit test
Bug: 64068300
Change-Id: If642d282cd8134060acf6ffe8d81215c394d800c

telecomm/java/android/telecom/ConnectionService.java

@@ -1387,6 +1387,7 @@ public abstract class ConnectionService extends Service {
                         connection.isRingbackRequested(),
                         connection.getAudioModeIsVoip(),
                         connection.getConnectTimeMillis(),
+                        connection.getConnectElapsedTimeMillis(),
                         connection.getStatusHints(),
                         connection.getDisconnectCause(),
                         createIdList(connection.getConferenceables()),
@@ -1798,6 +1799,7 @@ public abstract class ConnectionService extends Service {
                             null : conference.getVideoProvider().getInterface(),
                     conference.getVideoState(),
                     conference.getConnectTimeMillis(),
+                    conference.getConnectElapsedTime(),
                     conference.getStatusHints(),
                     conference.getExtras());
 
@@ -1863,6 +1865,7 @@ public abstract class ConnectionService extends Service {
                     connection.isRingbackRequested(),
                     connection.getAudioModeIsVoip(),
                     connection.getConnectTimeMillis(),
+                    connection.getConnectElapsedTimeMillis(),
                     connection.getStatusHints(),
                     connection.getDisconnectCause(),
                     emptyList,