[CrOS Wallpaper] Align arabic text correctly in top header contents.

Currently, the arabic text within the buttons of the top header contents
are misaligned.  This CL sets a line height that matches the font size
so that the text is aligned properly.

Before: https://screenshot.googleplex.com/0oXw7thLSmn
After: https://screenshot.googleplex.com/q2FWsqLdyKU

Fixed: 1038004
Change-Id: I26d091523797bef1543f310c314ace70f3eaf738
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1984471
Auto-Submit: Regan Hsu <hsuregan@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727869}

chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css

@@ -441,6 +441,7 @@ body:not([surprise-me-disabled]) [visibleif~='surprise-me-disabled'] {
   font-family: 'Roboto';
   font-size: 13px;
   font-weight: 500;
+  line-height: 13px;
 }
 
 :not(.no-images) .top-header-contents {