Fix slotted style for more-actions slot within settings-toggle-button.

Bug: 896581
Change-Id: Ie8542938f8eb92670ea17fd8a8feb9df91368040
Reviewed-on: https://chromium-review.googlesource.com/c/1297599Reviewed-by: Scott Chen <scottchen@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602216}

chrome/browser/resources/settings/controls/settings_toggle_button.html

@@ -46,7 +46,7 @@
 
       #labelWrapper,
       ::slotted([slot='more-actions']) {
-        margin-inline-end: var(--settings-control-label-spacing);
+        margin-inline-end: var(--settings-control-label-spacing) !important;
       }
 
       cr-policy-pref-indicator {