Fix size on gl-icon in app/assets/javascripts/error_tracking/components/error_details_info.vue

from: !173401 (comment 2228215103)

The icon on line 128 icon is designed for use at size 16.

For more information look at the gl-icon storybook entry: https://gitlab-org.gitlab.io/gitlab-ui/?path=/docs/base-icon--docs

Implementation Guide: change size to 16. make sure to add screenshots to MR