This PR introduces remove_unused_imports.sh script which wraps the same
upstream's tool and makes it usable at Brave repo.
Fixesbrave/brave-browser#31045
* Enable CheckJavaStyle presubmit check
For now severity for all checks except RedundantImport/UnusedImports
is changed from error to warning with brave-style-5.0.xml.
Once all Java style errors will be fixed, check should be switched
back to upstream's original check.
Fixesbrave/brave-browser#30823
* Remove all unused/redundant imports from java files