Allow Download button to be usable when the Dino easter egg is activated

components/security_interstitials/core/browser/resources/interstitial_v2.css

 /* Copyright 2014 The Chromium Authors. All rights reserved.
    Use of this source code is governed by a BSD-style license that can be
    found in the LICENSE file. */
 
 a {
   color: #585858;
 }
 
 .bad-clock .icon {
   background-image: -webkit-image-set(
@@ skipping 352 matching lines @@
   body .nav-wrapper {
     background: #f7f7f7;
     bottom: 0;
     box-shadow: 0 -22px 40px rgb(247, 247, 247);
     left: 0;
     margin: 0;
     max-width: 736px;
     padding-left: 24px;
     padding-right: 24px;
     position: fixed;
-    z-index: 1;
+    z-index: 2;
   }
 
   body.safe-browsing .nav-wrapper {
     background: rgb(206, 52, 38);
     box-shadow: 0 -22px 40px rgb(206, 52, 38);
   }
 
   .interstitial-wrapper {
     max-width: 736px;
   }
@@ skipping 268 matching lines @@
     width: 100%;
   }
 }
 
 @media (max-width: 239px) and (orientation: portrait) {
   .nav-wrapper {
     padding-left: 0;
     padding-right: 0;
   }
 }