Adjust Solr logging settings
Created by: pmather
Adjust the logging settings in /var/solr/log4j.properties so they are more like those in the "Taking Solr to Production" guide (https://cwiki.apache.org/confluence/display/solr/Taking+Solr+to+Product ion#TakingSolrtoProduction-Logsettings)
Specifically, we do the following:
- Disable the CONSOLE logger;
- Set the log rotation size threshold to a larger value ($SOLR_LOGSIZE).
(We also remove some redundant config.sh settings which should be set in config_PLATFORM.sh, namely APP_ENV and SOLR_CORE.)