machine_agent.rb recipe: extracting -> config change -> restart on every chef run

There are some conditions missing in the remote_file agent_zip and execute 'unzip-appdynamics-machine-agent' resource. On each chef run, the ZIP file is extracted again and the configuration file is been altered. This leads to a restart of the machine agent on every chef run.

Start with the machine_agent.rb recipe and inspect the remote_file agent_zip and execute 'unzip-appdynamics-machine-agent' resources. Reproduce a second Chef run without source changes; done means extraction, configuration changes, and machine-agent restarts occur only when their inputs require them.

Written by the indexing model from the issue text.