Do not show username for vulnerability details system notes

This makes sure the system notes in the vulnerability details
discussions section do not show the username.

Changelog: changed
EE: true

ee/app/assets/javascripts/vue_shared/security_reports/components/event_item.vue

@@ -52,6 +52,11 @@ export default {
       required: false,
       default: true,
     },
+    isSystemNote: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
   },
   computed: {
     noteId() {
@@ -72,6 +77,7 @@ export default {
         :author="author"
         :created-at="createdAt"
         :show-spinner="false"
+        :is-system-note="isSystemNote"
         class="gl-pb-0 gl-pl-0"
       >
         <slot name="header-message"><template v-if="createdAt">&middot;</template></slot>

ee/app/assets/javascripts/vulnerabilities/components/history_entry.vue

@@ -34,6 +34,7 @@ export default {
       :author="systemNote.author"
       :created-at="systemNote.createdAt"
       :icon-name="systemNote.systemNoteIconName"
+      is-system-note
       icon-class="timeline-icon m-0"
       class="m-3"
     >

ee/spec/frontend/vue_shared/security_reports/components/event_item_spec.js

@@ -38,6 +38,7 @@ describe('Event Item', () => {
         author: propsData.author,
         createdAt: propsData.createdAt,
         showSpinner: false,
+        isSystemNote: false,
       });
     });
 
@@ -126,4 +127,20 @@ describe('Event Item', () => {
       expect(noteHeader().text()).not.toContain('·');
     });
   });
+
+  it('passes `isSystemNote` prop to note header component', () => {
+    const propsData = {
+      id: 123,
+      createdAt: 'createdAt',
+      headerMessage: 'header message',
+      author: {
+        name: 'Tanuki',
+        username: 'gitlab',
+      },
+      isSystemNote: true,
+    };
+    mountComponent({ propsData });
+
+    expect(noteHeader().props('isSystemNote')).toBe(true);
+  });
 });

ee/spec/frontend/vulnerabilities/history_entry_spec.js

@@ -50,6 +50,7 @@ describe('History Entry', () => {
       author: systemNote.author,
       createdAt: systemNote.createdAt,
       iconName: systemNote.systemNoteIconName,
+      isSystemNote: true,
     });
   });