test_serialization in libcore.java.nio.file are failing

_hex_ is a string representing a serialized exception in hex.
_hex1_ is obtained by deserializing and serializing _hex_.
When comparing _hex_ and _hex1_, _hex1_ is lowercase and _hex_ is uppercase.
If we do a comparison case insensitive, the start and end match but there is a section in the middle that is different.

Issue occurs for:
- AccessDeniedExceptionTest.java
- AtomicMoveNotSupportedExceptionTest.java
- DirectoryNotEmptyExceptionTest.java
- FileAlreadyExistsExceptionTest.java
- FileSystemExceptionTest.java
- FileSystemLoopExceptionTest.java
- NoSuchFileExceptionTest.java
- NotDirectoryExceptionTest.java
- NotLinkExceptionTest.java

Issue does not occur for:
- DirectoryIteratorExceptionTest.java
- FileSystemAlreadyExistsExceptionTest.java
- FileSystemNotFoundExceptionTest.java
- InvalidPathExceptionTest.java
- ProviderMismatchExceptionTest.java
- ProviderNotFoundExceptionTest.java