Update assets/sass/protocol/components/_menu.scss

Co-authored-by: Copilot <[email protected]>

Author: stephaniehobson

assets/sass/protocol/components/_menu.scss

@@ -75,6 +75,7 @@
 
         &::before {
             background: $url-image-expand-black top left no-repeat;
+            background-size: 20px 20px;
             @include bidi(((right, 8px, left, auto),));
             transition: transform 100ms ease-in-out;
             content: '';