Disable Registries other than standard Registry by default (Secure by default)

[suzuki-shunsuke]

What is changed

Registries other than standard Registry are disabled by default.
The following types of registries are disabled.

• local
• github_content

It would fail to install or execute packages of these registries by aqua Policy.
To use these registries, you have to set aqua Policy explicitly.

Why this change is needed

To make aqua secure by default.
aqua should be secure without special setting.

For many users registries other than standard registry is unneeded.
These registries can be abused.