iface-modem-voice: recheck call state polling when call is started

When an outgoing call is created and added to the call list its state
is UNKNOWN. The call list emits the ADDED signal which MMIfaceModemVoice
listens for to check whether to begin polling call state.

But since UNKNOWN is not an in-progress call state polling isn't started.
And nothing was rechecking whether to start polling when the call state
changed to something other than UNKNOWN.

Do that so that we can track call progress as it dials out and is
answered.

Signed-off-by: Dan Williams <dan@ioncontrol.co>

src/mm-iface-modem-voice.c

@@ -32,6 +32,10 @@ static GQuark in_call_event_context_quark;
 
 G_DEFINE_INTERFACE (MMIfaceModemVoice, mm_iface_modem_voice, MM_TYPE_IFACE_MODEM)
 
+static void setup_call_list_polling (MMCallList        *call_list,
+                                     const gchar       *call_path_added,
+                                     MMIfaceModemVoice *self);
+
 /*****************************************************************************/
 
 void
@@ -1781,6 +1785,7 @@ typedef enum {
     IN_CALL_SETUP_STEP_FIRST,
     IN_CALL_SETUP_STEP_UNSOLICITED_EVENTS,
     IN_CALL_SETUP_STEP_AUDIO_CHANNEL,
+    IN_CALL_SETUP_STEP_CHECK_POLLING,
     IN_CALL_SETUP_STEP_LAST,
 } InCallSetupStep;
 
@@ -1908,6 +1913,10 @@ in_call_setup_context_step (GTask *task)
         }
         ctx->step++;
         /* fall-through */
+    case IN_CALL_SETUP_STEP_CHECK_POLLING:
+        setup_call_list_polling (NULL, NULL, self);
+        ctx->step++;
+        /* fall-through */
     case IN_CALL_SETUP_STEP_LAST:
         g_task_return_boolean (task, TRUE);
         g_object_unref (task);