Install and configure (Red Hat) in glance: missing DB steps

[Michael Burk]

This bug tracker is for errors with the documentation, use the following as a template and remove or add fields as you see fit. Convert [ ] into [x] to check boxes:

- [x] This doc is inaccurate in this way: Under Prerequisites, the database setup shows to connect to the db, and then it skips to the CLI to create the glance user. Compare to Ocata doc:
https://docs.openstack.org/ocata/install-guide-rdo/glance-install.html#install-and-configure-components
- [ ] This is a doc addition request.
- [ ] I have a fix to the document that I can paste below including example: input and output.

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 - Ask OpenStack: http://ask.openstack.org
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-----------------------------------
Release: 15.0.0.0rc2.dev25 on 'Wed Aug 23 03:33:04 2017, commit 9820166'
SHA: 982016670fe908e5d7026714b115e63b7c31b46b
Source: https://git.openstack.org/cgit/openstack/glance/tree/doc/source/install/install-rdo.rst
URL: https://docs.openstack.org/glance/pike/install/install-rdo.html