message: feat(GUI): replace ng-show and ng-hide with ng-if
  We replace `ng-show/hide` with `ng-if` on the main page in order to
  remove unnecessary calls and become more efficient.
  Changelog-Entry: Replace ng-show/hide with ng-if on main page.
  Change-Type: patch
diff: </div>
  <div class="space-vertical-large">
  - <div ng-hide="main.selection.hasImage()">
  + <div ng-if="!main.selection.hasImage()">
  <button
  class="button button-primary button-brick"
  tabindex="{{ main.selection.hasImage() ? -1 : 1 }}"
  </div>
  <div class="space-vertical-large">
  - <div ng-hide="main.selection.hasDrive()">
  + <div ng-if="!main.selection.hasDrive()">
  <div>
  <button class="button button-primary button-brick"
  </div>
  </div>
  - <div ng-show="main.selection.hasDrive()">
  + <div ng-if="main.selection.hasDrive()">
  <div class="step-selection-text"
  ng-class="{
  <span ng-bind="flash.getProgressButtonLabel()"></span>
  </progress-button>
  - <p class="step-footer step-footer-split" ng-show="main.state.getFlashState().speed && main.state.getFlashState().percentage != 100">
  + <p class="step-footer step-footer-split" ng-if="main.state.getFlashState().speed && main.state.getFlashState().percentage != 100">
  <span ng-bind="main.state.getFlashState().speed.toFixed(2) + ' MB/s'"></span>
  <span>ETA: {{ main.state.getFlashState().eta | secondsToDate | amDateFormat:'m[m]ss[s]' }}</span>
  </p>
  