* Increase the default complexity of DB passwords in order to meet password_validation_policy.default_complexity
* Use password_validation_policy.min_length if provided
* Explicitly generate a root_password if not provided
* Use object (password, random_password) for root_password config
* Make root_password non-nullable, and add validation against specifying both a password and `random_password`.
Fix test for stronger password generation.
* Add example for root_password and password_validation_policy
* Rerun tfdoc.py
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Co-authored-by: Julio Castillo <jccb@google.com>
