Autocomplete accessibility issues

[spacedmonkey]

When running the automated accessibility tests in #3294 the follow errors where found with the autocomplete component.

  Rule: "aria-input-field-name" (ARIA input fields have an accessible name)
    Help: https://dequeuniversity.com/rules/axe/3.3/aria-input-field-name?application=axe-puppeteer
    Affected Nodes:
      #amp-stories-font-family-picker-1__listbox
        Fix ANY of the following:
        - aria-label attribute does not exist or is empty
        - aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
        - Element has no title attribute or the title attribute is empty

    Rule: "aria-required-children" (Certain ARIA roles must contain particular children)
    Help: https://dequeuniversity.com/rules/axe/3.3/aria-required-children?application=axe-puppeteer
    Affected Nodes:
      #amp-stories-font-family-picker-1__listbox
        Fix ANY of the following:
        - Required ARIA child role not present: option

   Rule: "aria-valid-attr-value" (ARIA attributes must conform to valid values)
    Help: https://dequeuniversity.com/rules/axe/3.3/aria-valid-attr-value?application=axe-puppeteer
    Affected Nodes:
      #amp-stories-font-family-picker-3
        Fix ALL of the following:
          - Invalid ARIA attribute value: aria-activedescendant="false".

    Rule: "listitem" (<li> elements must be contained in a <ul> or <ol>)
    Help: https://dequeuniversity.com/rules/axe/3.3/listitem?application=axe-puppeteer
    Affected Nodes:
      .autocomplete__option
        Fix ANY of the following:
        - List item does not have a <ul>, <ol> or role="list" parent element