We don't care where in the output tree the file is produced, so that
there is no need to wrap the java_library rule, that is used by
java_sources bucklet with java_binary rule. java_library produces the
output artifact one directory deeper compared to java_binary, but it
doesn't matter:
$ buck targets --show_output gerrit-acceptance-framework:src
buck-out/gen/gerrit-acceptance-framework/lib__src__output/src.jar
$ buck targets --show_output gerrit-acceptance-framework:acceptance-framework-src
buck-out/gen/gerrit-acceptance-framework/acceptance-framework-src.jar
Change-Id: Id77752f179b8ee2a8217ab57d2978aaade714d27
bf9634f1df