Fix for manage_keyring behavior.

- code refactoring to simplify syntax
- admin keyring is managed by managed_keyring state
- if caps for admin keyring are defined, use old logic
- grains are not used during keyring management as expected now
- doc fix

Prod-Related: PROD-32112
Change-Id: I90b13e3dc57d2da394f166165100870e09e6ada3
6 files changed