Fix file permissions and command args for logstash

Logstash stubbornly demands to be able to read its config files and
doesn't like to be told about a plugin directory that doesn't exist.
Java also really wants us to specify the location of the jar file that
we are attempting to execute.

Change-Id: Iad8822ce5612d3e0c9370a5a6d27dd54ce2ede6d
Merge "Fix file permissions and command args for logstash" into production