refactor: remove unused test-module in java-sdk

[gouravkrosx]

Related Issue

• NA

Describe the changes you've made

• Removed unused test-module in java-sdk.
• Ugrade java-sdk version to 1.2.8 in readMe.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, local variables)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Please describe the tests(if any). Provide instructions how its affecting the coverage.

Describe if there is any unusual behaviour of your code(Write NA if there isn't)

NA

Checklist:

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas and used java doc.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.

Screenshots (if any)

Original	Updated
original screenshot	updated screenshot