[Java] Fix the bugs when calculating vector hash code #23333
Description
When calculating the hash code for a value in the vector, the validity bit must be taken into account.
Reporter: Liya Fan / @liyafan82
Assignee: Liya Fan / @liyafan82
PRs and other links:
Note: This issue was originally created as ARROW-7020. Please see the migration documentation for further details.