Context attributes are not passed to component variants.

Consider an area which uses a custom template script:

areas:
  main:
    templateScript: /travel-demo/templates/pages/mainArea.ftl

In the script we pass contextAttributes to the component:

[#list components as component ]
  [@cms.component contextAttributes={"indexString":indexString, "useIndex":useIndex}/]
[/#list] 

When trying to access the context attributes in the component script they are lost when component variants are in place.

${ctx.indexString}
${ctx.useIndex}

Reproduce

1. Create an area script which passes attributes.
2. Configure the templateScript in the page template definition.
3. Create a page with two components.
4. Add a component variant to one of the components.

Actual
The component with variants cannot access the passed contextAttributes. The regular (non-variant) component can.

Expected
The contextAttributes should be accessible in the component variant.