Removed findbugs from the hadoop build images and added spotbugs instead.
Upgraded SpotBugs to 4.2.2 and spotbugs-maven-plugin to 4.2.0.
Reviewed-by: Masatake Iwasaki <iwasakims@apache.org>
(cherry picked from commit 23b343aed1)
Conflicts:
dev-support/docker/Dockerfile
hadoop-project/pom.xml