Revert "Fix Print Preview sidebar outline"

This reverts commit d12f01a6.

Reason for revert: Causes crbug.com/907378, and the Blink change that
caused that bug is expected to be reverted.

Original change's description:
> Fix Print Preview sidebar outline
> 
> The scroller is now focusable due to Blink changes at r608013.
> Remove the outline and take it out of the tab order.
> 
> Bug: 905604
> Change-Id: Ib8154c691e1240b27118288950c8efdf46c803b6
> Reviewed-on: https://chromium-review.googlesource.com/c/1343285
> Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
> Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#609495}

TBR=dpapad@chromium.org,rbpotter@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 905604
Change-Id: Iea4a67f80284091c2acf0fee24215a7f5b174a03
Reviewed-on: https://chromium-review.googlesource.com/c/1344837Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610184}

chrome/browser/resources/print_preview/new/app.html

@@ -66,7 +66,6 @@
       #container {
         color: var(--google-grey-900);
         flex: 1;
-        outline: none;
         overflow: overlay;
         padding-bottom: 16px;
       }
@@ -95,7 +94,7 @@
           on-print-requested="onPrintRequested_"
           on-cancel-requested="onCancelRequested_">
       </print-preview-header>
-      <div id="container" tabindex="-1">
+      <div id="container">
         <print-preview-destination-settings id="destinationSettings"
             destination="[[destination_]]"
             destination-store="[[destinationStore_]]"