4.17.0 values.schema.json doesn't allow for fullnameOverride

[sharkymcdongles]

When upgrading to 4.17.0, fullnameOverride is no longer allowed due to the new values.schema.json file:

✗ Helm upgrade failed: values don't meet the specifications of the schema(s) in the following chart(s):
atlantis:
- (root): Additional property fullnameOverride is not allowed

Either remove the value or allow it in the schema.

[cilindrox]

In addition to the above, I'm also running into an issue with the global prop not being allowed:

atlantis:
- (root): Additional property global is not allowed

This is triggered when including Atlantis as a subchart/dep.

[KeenanLawrence]

This value is still being used in the _helpers.tpl. Particularly important for our use case because we require a specific service name and this (or nameOverride) is the only way to set it.

[jamengual]

@roytev