MT#62266 SessionTimer: init `remote_timer_aware`

Just by default construct as true.

By default we always assume that remote side supports SST timers,
unless not proved the opposite with absent SST related headers
in any first seen 200OK or INVITE/UPDATE request.
Then it gets disabled.

This policy is quite explicit and allows to gracefully
step back from SST scheduling, if remote side doesn't support timers.

Change-Id: I422c76c42d44bcf2e775ffb9afa5842a9def1402

core/plug-in/session_timer/SessionTimer.cpp

@@ -54,7 +54,11 @@ SessionTimer::SessionTimer(AmSession* s)
    session_interval(0),
    min_se(0),
    session_refresher(refresh_remote),
-   accept_501_reply(true)
+   accept_501_reply(true),
+   remote_timer_aware(true) /* by default always give a chance! until not proven the opposite */
+   /* TODO: should we init also `session_refresher_role`?
+    * rather not because each leg from B2B perspective can be either UAS or UAC.
+    */
 {
 }