support ECJ linting on newer JDK versions
support ECJ linting on newer JDK versions

The entire precommit task will still fail with unsupported java version
(subsequent checks do not support the newer javadocs format).

But this allows the ECJ linter to run, which checks for things such as
unused imports.

apache/solr,apache/solr,apache/solr,apache/solr,apache/solr