MOBILE-3833 forum: Display locked discussion icon

src/addons/mod/forum/components/index/index.html

@@ -56,6 +56,8 @@
                             <core-format-text [text]="discussion.subject" contextLevel="module" [contextInstanceId]="module && module.id"
                                 [courseId]="courseId">
                             </core-format-text>
+                            <ion-icon name="fas-lock" *ngIf="discussion.locked" class="addon-mod-forum-locked-icon"
+                                [attr.aria-label]="'addon.mod_forum.discussionlocked' | translate"></ion-icon>
                         </p>
                         <ion-button *ngIf="canPin || discussion.canlock || discussion.canfavourite" fill="clear"
                             [attr.aria-label]="('core.displayoptions' | translate)" (click)="showOptionsMenu($event, discussion)">

src/addons/mod/forum/components/index/index.scss

@@ -18,6 +18,11 @@
 
                 ion-icon {
                     @include margin(0, 6px, 0, 0);
+
+                    &.addon-mod-forum-locked-icon {
+                        @include margin-horizontal(4px, 0px);
+                        color: var(--gray-500);
+                    }
                 }
 
             }