Summary:
1. [Path] sections do not belong in the .service files. We could have moved them
   into a .path file, but that only controls the automatic activation of a unit file. Because
   we manage this directly, we do not get much use - and we are not losing functionality
   since these directives are currently ignored anyways
2. Updated standardoutput/error directives to use journal over syslog - syslog is now
   deprecated, and we are expected to use journal

Test Plan: itests pass

Reviewers: anijhawan, nsingh, muthu

Reviewed By: nsingh

Differential Revision: https://phorge.dev.yugabyte.com/D45931