MD Settings: Fix size and padding of expand button

ui/webui/resources/cr_elements/shared_style_css.html

Index: ui/webui/resources/cr_elements/shared_style_css.html
diff --git a/ui/webui/resources/cr_elements/shared_style_css.html b/ui/webui/resources/cr_elements/shared_style_css.html
index fc3897744479edd15d33b5506db0e1bfea305f16..e34ab9a1c0803f556962975b84c53029135e763c 100644
--- a/ui/webui/resources/cr_elements/shared_style_css.html
+++ b/ui/webui/resources/cr_elements/shared_style_css.html
@@ -41,6 +41,16 @@
         @apply(--cr-actionable);
       }
 
+      button[is='paper-icon-button-light'] {
+        @apply(--cr-paper-icon-button-margin);
+        background-position: center;
+        background-repeat: no-repeat;
+        background-size: var(--cr-icon-size);
+        flex-shrink: 0;
+        height: var(--cr-icon-ripple-size);
+        width: var(--cr-icon-ripple-size);
+      }
+
       button[is='paper-icon-button-light'].subpage-arrow {
         background-image: url(../images/arrow_right.svg);
       }
@@ -54,6 +64,10 @@
         display: none;
       }
 
+      paper-icon-button.subpage-arrow {
+        background-image: url(../images/arrow_right.svg);
+      }
+
       [actionable] :-webkit-any(.subpage-arrow, .icon-external),
       [actionable]:-webkit-any(.subpage-arrow, .icon-external) {
         display: block;