Fix checkstyle

Author: zoewangg

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/async/ChunkBuffer.java

@@ -19,7 +19,6 @@
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicLong;