Update VolumeApiServiceImplTest.java

Author: Dajeong-Park

server/src/test/java/com/cloud/storage/VolumeApiServiceImplTest.java

@@ -36,7 +36,6 @@
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.ExecutionException;