[JavaWorker] Java code lint check and binding to CI

[salah-man]

. Use the maven-checkstyle-plugin for java code lint check and Google Style for the rules, which is almost the same as Apache Arrow.
. Fix the java code lint problem in the whole java package.
. Add the java code lint check in CI.

[AmplabJenkins]

Test PASSed.
Refer to this link for build results (access rights to CI server needed):
https://amplab.cs.berkeley.edu/jenkins//job/Ray-PRB/5966/
Test PASSed.

[pcmoritz]

Thanks, LGTM! All the changes in this PR are just linting related, right? I checked some of it but not all.

[robertnishihara]

Thanks @salah-man!

[salah-man]

Yes,it is all the changes of this PR is about java code lint and all of the changed files are under the java package.