Update usage of instance

Signed-off-by: Mario Danic <mario@lovelyhq.com>

app/src/main/java/com/nextcloud/talk/controllers/CallNotificationController.java

@@ -222,7 +222,7 @@ public class CallNotificationController extends BaseController {
                         for (Room room : roomsOverall.getOcs().getData()) {
                             if (roomId.equals(room.getRoomId())) {
                                 currentRoom = room;
-                                conversationNameTextView.setText(room.getDisplayName());
+                                conversationNameTextView.setText(currentRoom.getDisplayName());
                                 loadAvatar();
                                 checkIfAnyParticipantsRemainInRoom();
                                 showAnswerControls();