--resolve FS-4461

Add record_seconds, record_ms and record_samples variables done recording.
original patch not used due to refactor in code.

src/switch_ivr_async.c

@@ -1212,6 +1212,12 @@ static switch_bool_t record_callback(switch_media_bug_t *bug, void *user_data, s
 				switch_event_fire(&event);
 			}
 
+			if (read_impl.actual_samples_per_second) {
+				switch_channel_set_variable_printf(channel, "record_seconds", "%d", rh->fh->samples_out / read_impl.actual_samples_per_second);
+				switch_channel_set_variable_printf(channel, "record_ms", "%d", rh->fh->samples_out / (read_impl.actual_samples_per_second / 1000));
+			}
+			switch_channel_set_variable_printf(channel, "record_samples", "%d", rh->fh->samples_out);
+
 			switch_channel_execute_on(channel, SWITCH_RECORD_POST_PROCESS_EXEC_APP_VARIABLE);
 
 			if ((var = switch_channel_get_variable(channel, SWITCH_RECORD_POST_PROCESS_EXEC_API_VARIABLE))) {