🐛 fix: 패키지 변경 관련 에러 수정

Author: jiwon1217

backend/src/main/java/io/f1/backend/domain/game/app/RoomService.java

@@ -12,6 +12,7 @@
 import static io.f1.backend.domain.quiz.mapper.QuizMapper.toGameStartResponse;
 import static io.f1.backend.global.security.util.SecurityUtils.getCurrentUserId;
 import static io.f1.backend.global.security.util.SecurityUtils.getCurrentUserNickname;
+import static io.f1.backend.global.security.util.SecurityUtils.getCurrentUserPrincipal;
 
 import io.f1.backend.domain.game.dto.MessageType;
 import io.f1.backend.domain.game.dto.RoomEventType;