message: feat(template): replace "update" text label to icon at Images -> Zones Tab for image
diff: </mdl-tab-panel-title>
  <mdl-tab-panel-content *loading="updating">
  <div *ngIf="!readyInEveryZone" class="update-button-container">
  - <mdl-button (click)="updateStatus()">{{ 'UPDATE' | translate }}</mdl-button>
  + <button
  + mdl-button
  + mdl-ripple
  + mdl-button-type="icon"
  + mdTooltipPosition="before"
  + [mdTooltip]="'UPDATE' | translate"
  + (click)="updateStatus()"
  + >
  + <mdl-icon>sync</mdl-icon>
  + </button>
  </div>
  <mdl-card *ngFor="let zone of template.zones" class="vm-card" mdl-shadow="2">
  <mdl-card-title>
  