Update upload a license file docs

app/views/admin/application_settings/general.html.haml

doc/user/admin_area/license.md

...riptions/show/components/subscription_activation_card.vue

.../subscriptions/show/components/subscription_breakdown.vue

...ascripts/admin/subscriptions/show/mount_cloud_licenses.js

ee/app/helpers/license_helper.rb

.../views/admin/application_settings/_license_file.html.haml

ee/spec/features/admin/admin_settings_spec.rb

...ures/admin/subscriptions/admin_views_subscription_spec.rb

...ions/show/components/subscription_activation_card_spec.js

...scriptions/show/components/subscription_breakdown_spec.js

ee/spec/helpers/license_helper_spec.rb

locale/gitlab.pot

qa/qa/ee/page/admin/license.rb

qa/qa/ee/resource/license.rb