When starting the keystone-api pod, the service checks for a
access_rules file for application credentials during startup.
If the file does not exist, keystone emits a warning saying the
file is not found:
WARNING keystone.access_rules_config.backends.json [-] No config
file found for access rules, application credential access rules
will be unavailable.: FileNotFoundError: [Errno 2] No such file
or directory: '/etc/keystone/access_rules.json'
This change adds in a blank access_rules.json file to the
keystone etc directory in order to surpress this message.
Change-Id: I63ac153cc91ac45b3fd223f8a54b933b5cbffac4
fe53b5e559