update xaxis.java

[AbidFaiz]

PR Checklist:

• I have tested this extensively and it does not break any existing behavior.
• I have added/updated examples and tests for any new behavior.
• If this is a significant change, an issue has already been created where the problem / solution was discussed: [N/A, or add link to issue here]
  

PR Description

[AbidFaiz]

change in barchart xaxis content position top to bottom