Enable project access tokens by default - self-managed

What

Project access tokens is currently off by default and behind the resource_access_token feature flag. When we're confident in the feature on self-managed, we should enable this flag by default and consider removing it in a future release.

• Enable resource_access_token by default.

Owners

• Team: ~"group::access"
• Most appropriate slack channel to reach out to: #g_manage_access
• Best individual to reach out to: Melissa Ushakov

Expectations

What are we expecting to happen?

For self-managed instances, users can create Project Access Tokens in "Project" -> "Settings" -> "Access Tokens"

What might happen if this goes wrong?

Users can not create Project Access Tokens

What can we monitor to detect problems with this?

Self-managed only right now, customer feedback and support will be the best way to monitor