fix(java): fix the exception when a string contains unicode characters (

arrow-udf#33)

Signed-off-by: Runji Wang <[email protected]>

The length allocated for StringArray should be the number of bytes, but
it was the number of unicode chars.

---------

Signed-off-by: Runji Wang <[email protected]>

release java sdk

Signed-off-by: Runji Wang <[email protected]>