Unable to set anonymous access in server default configuration

Problem Definition

Bitbucket support public access for anonymous users however it requires the manual step to enable the checkbox in repository/project setting.
https://confluence.atlassian.com/bitbucketserver/allowing-public-access-to-code-776639799.html
There's no option to configure as a bitbucket server's global default option.

Suggested Solution

Enable anonymous access via bitbucket.properties

Why this is important

Because developers in open-source project (e.g. github users) get used to public repository in default configuration.

Workaround

Follow the step and make projects/repositories public manually.
https://confluence.atlassian.com/bitbucketserver/allowing-public-access-to-code-776639799.html