Clean up interface method declarations by removing redundant public modifiers

[ThirdGoddess]

Purpose

This pull request makes a small stylistic cleanup of nested interface method declarations.
Some methods currently include the public modifier while others rely on Java’s implicit visibility.
This inconsistency is purely visual and does not affect functionality.
Removing the redundant modifiers improves readability and enforces a consistent code style.


Description

In Java, interface methods are implicitly public, so explicitly declaring public is unnecessary.
This PR removes the redundant public keywords from nested interface methods throughout the codebase.

No behavior or public API changes are introduced.
The change is intended solely to make the code easier to read, review, and maintain.


Checklist

• New code follows the Google Java Style Guide
  This is automatically checked by mvn verify, but can also be checked on its own using mvn spotless:check.
  Style violations can be fixed using mvn spotless:apply; this can be done in a separate commit to verify that it did not cause undesired changes.
• No API behavior or signature changes
• No new tests required
• mvn clean verify javadoc:jar passes without errors
  

[eamonnmcmanus]

This makes sense. Google's internal "Java Practices" guide calls for omitting redundant modifiers like these.