License check: make sure no offensive libs introduced.

[justinmclean]

Check the license of all dependencies to ensure they are compatible with the Apache license version 2.

[justinmclean]

Checked all dependencies and licenses and all are compatible with the Apache license. Checked via dependency license report gradle plugin. LICENSE and NOTICE need minor updates due to added ALv2 3rd party files.

[jerryshao]

@justinmclean Do you have related PR to address the issue you mentioned above?

[justinmclean]

Not yet, as I discovered a license issue, and that will need to be resolved first.

[justinmclean]

While it is difficult to know for sure as changes have been made I'm going to assume the extra files with ASF headers come from Hadoop.