Fix import button width on Issue list page

Changelog: fixed

app/assets/javascripts/issuable/components/csv_import_export_buttons.vue

@@ -102,6 +102,7 @@ export default {
         :text="$options.i18n.importIssuesText"
         :text-sr-only="!showLabel"
         :icon="importButtonIcon"
+        class="gl-w-full gl-md-w-auto"
       >
         <gl-dropdown-item v-gl-modal="importModalId">
           {{ $options.i18n.importCsvText }}

app/assets/javascripts/issues/list/components/issues_list_app.vue

@@ -785,7 +785,7 @@ export default {
           </gl-button>
           <csv-import-export-buttons
             v-if="showCsvButtons"
-            class="gl-mr-3"
+            class="gl-w-full gl-sm-w-auto gl-sm-mr-3"
             :export-csv-path="exportCsvPathWithQuery"
             :issuable-count="currentTabCount"
           />

app/views/shared/empty_states/_issues.html.haml

@@ -47,7 +47,7 @@
               = link_to _('New issue'), button_path, class: 'gl-button btn btn-confirm', id: 'new_issue_link'
 
             - if show_import_button
-              .js-csv-import-export-buttons{ data: { show_import_button: 'true', issuable_type: issuable_type, import_csv_issues_path: import_csv_namespace_project_issues_path, can_edit: can_edit.to_s, project_import_jira_path: project_import_jira_path(@project), max_attachment_size: number_to_human_size(Gitlab::CurrentSettings.max_attachment_size.megabytes), container_class: 'gl-display-inline-flex gl-vertical-align-middle', show_label: 'true' } }
+              .js-csv-import-export-buttons{ data: { show_import_button: 'true', issuable_type: issuable_type, import_csv_issues_path: import_csv_namespace_project_issues_path, can_edit: can_edit.to_s, project_import_jira_path: project_import_jira_path(@project), max_attachment_size: number_to_human_size(Gitlab::CurrentSettings.max_attachment_size.megabytes), container_class: 'gl-w-full gl-sm-w-auto gl-sm-mr-3 gl-display-inline-flex gl-vertical-align-middle', show_label: 'true' } }
         %hr
         %p.gl-text-center.gl-mb-0
           %strong