[CCA] Fix y-offset of shadow on setting icon

The icon is composed by the shape of setting itself and the shadow with
offset plus blur effect. Set the y-offset of shadow to 0 to be
consistent with other icon.

Bug: 1012924
Test: Check the shadow of setting icon after change.
Change-Id: I50c716e26cda14eb084449ece039763c8a41a2ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1981516
Commit-Queue: Kuo Jen Wei <inker@chromium.org>
Commit-Queue: Shik Chen <shik@chromium.org>
Auto-Submit: Kuo Jen Wei <inker@chromium.org>
Reviewed-by: Shik Chen <shik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727402}

chrome/browser/resources/chromeos/camera/src/images/camera_button_settings.svg

 <svg width="24px" height="24px" viewBox="0 0 24 24" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
     <defs>
         <filter x="-52.5%" y="-52.5%" width="205.0%" height="205.0%" filterUnits="objectBoundingBox" id="filter-1">
-            <feOffset dx="0" dy="2" in="SourceAlpha" result="shadowOffsetOuter1"></feOffset>
+            <feOffset dx="0" dy="0" in="SourceAlpha" result="shadowOffsetOuter1"></feOffset>
             <feGaussianBlur stdDeviation="1.5" in="shadowOffsetOuter1" result="shadowBlurOuter1"></feGaussianBlur>
             <feColorMatrix values="0 0 0 0 0.125490196   0 0 0 0 0.129411765   0 0 0 0 0.141176471  0 0 0 0.3 0" type="matrix" in="shadowBlurOuter1" result="shadowMatrixOuter1"></feColorMatrix>
             <feMerge>