Packaging: Allow to configure ES_GC_LOG_FILE

This deprecates the ES_USE_GC_LOGGING environment variable and adds
support to the packages for setting the ES_GC_LOG_FILE in
/etc/sysconfig and /etc/defaults

This is based on #8479 by Andreas Kohn and just changes minor things
and removes ES_USE_GC_LOGGING

Conflicts:
	bin/elasticsearch.in.bat
	bin/elasticsearch.in.sh
	src/deb/init.d/elasticsearch
	src/rpm/sysconfig/elasticsearch