The policy-and-docs-in-code Queens goal outlines the work
required for projects to move policy into code and document the
operations and defaults.
This commit replaces occurrences of RuleDefault
with DocumentedRuleDefault where appropriate,
which requires additional attributes when used that supply more
documentation in rendered policy files.
Using DocumentedRuleDefault produces more descriptive generated policy
descriptons in 'configuration' section of ironic docs.
Change-Id: Idc35a5fbe2583e5fd712108a48eb9cec7cbecb76
Closes-Bug: #1716772
297ef395e4