Elasticsearch version: Version: 6.5.4, Build: oss/rpm/d2ef93d/2018-12-17T21:17:40.758843Z, JVM: 1.8.0_191

Plugins installed: []

JVM version:
openjdk version "1.8.0_191"
OpenJDK Runtime Environment (build 1.8.0_191-b12)
OpenJDK 64-Bit Server VM (build 25.191-b12, mixed mode)

OS version: CentOS Linux release 7.5.1804 (Core)

Description of the problem including expected versus actual behavior:
After installing elasticsearch official rpm the group of the file /etc/sysconfig/elasticsearch is overwritten by the spec file itself in the post section:
rpm -qV elasticsearch
S.5...GT. c /etc/sysconfig/elasticsearch

This is not best practice because user may restore the original group by using:
rpm --setugids elasticsearch

I expect that the files section of the spec file contains:
%config(noreplace) %attr(0664, root, root) /etc/sysconfig/elasticsearch
instead of:
%config(noreplace) %attr(0660, root, root) "/etc/sysconfig/elasticsearch"

Steps to reproduce:

1. install elasticsearch on a Centos 7
2. systemctl status elasticsearch should show elasticsearch running
3. restore original group of elasticsearch by using rpm --setugids elasticsearch
4. systemctl restart elasticsearch
5. systemctl status elasticsearch shows that elasticsearch fails to start