Simplify doclava build.gradle

- Update to using maven-publish plugin (maven is deprecated)
- Remove code for distributing doclava ab/ub-doclava-master has
  been disabled since 2017
- Remove support for unbundled build, it does not fully work anyway
- Update dependencies block to use modern implementation configuration
  instead of deprecated compile

Test: ./gradlew distpublicDocsdistpublicDocs still works
Change-Id: Ib9d10b5808a281f596938cf244fabda75b43bd4d
1 file changed