WPT tests related to sectionheader and sectionfooter need to be updated

[tranjocelyn]

I have the implementation for the new sectionheader and sectionfooter roles ready for Chrome, but it's currently failing the following subtests in WPT:

el-footer, el-header, and el-header-ancestormain in wpt/html-aam/roles-contextual.html footer element scoped to main element is generic in wpt/wai-aria/role/contextual-roles.html

I believe these subtests should be expecting the sectionheader/sectionfooter roles instead of generic.