Fix the resource leak within the tests

[Jackie-Jiang]

When running tests with java 21 with skip bytebuffers:true, we can detect resource leaks through the finalize() method within DirectMemory and MmapMemory class.
Here are example messages indicating resource leak in the test:

00:51:33.864 WARN [DirectMemory] [Finalizer] Direct memory of size: 4000 wasn't explicitly closed
00:51:33.864 WARN [MmapMemory] [Finalizer] Mmap section of size: 1618 wasn't explicitly closed

We should go over the test log and fix all the buffers not explicitly closed.

[abhioncbr]

seems like this issue is also the same.

Please assign it to me; I will give it a try to fix it. Thanks