Register default policies in code

This commit registers all policies formally kept in policy.json as
defaults in code. This is an effort to make policy management easier
for operators. More information on this initiative can be found
below:

  https://governance.openstack.org/tc/goals/queens/policy-in-code.html

bp policy-and-docs-in-code

Change-Id: Ibab08f8e1c95b86e08737c67a39c293566dbabc7

tox.ini

@@ -46,6 +46,10 @@ sitepackages = False
 commands =
     oslo-config-generator --config-file etc/watcher/oslo-config-generator/watcher.conf
 
+[testenv:genpolicy]
+commands =
+    oslopolicy-sample-generator --config-file etc/watcher/oslo-policy-generator/watcher-policy-generator.conf
+
 [flake8]
 show-source=True
 ignore= H105,E123,E226,N320,H202