fix(material/slide-toggle): increase slide toggle touch target

Updates Angular Components Slide Toggle component and increases
the touch target to meet strict accessibility guidelines of buttons
having a minimum touch target of 48x48 pixels.

Fixes b/265033905

Author: essjay05

src/material/slide-toggle/slide-toggle.scss

@@ -21,6 +21,27 @@ $fallbacks: m3-slide-toggle.get-tokens();
   padding: 0;
   position: relative;
 
+  &::after {
+    $_touch-target-size: 48px;
+    $_ripple-size: 24px;
+    $offset: 5px;
+  
+    content: '';
+    opacity: 0;
+    display: block;
+    position: absolute;
+    top: 0 - $offset;
+    bottom: 0 - $offset;
+    left: $offset;
+    right: $offset;
+    border-radius: 50%;
+    box-sizing: border-box;
+    padding: calc(($_touch-target-size - $_ripple-size)/2);
+    margin: calc((($_touch-target-size - $_ripple-size)/2) * -1);
+    // stylelint-disable material/no-prefixes
+    background-clip: content-box;
+  }
+
   width: token-utils.slot(slide-toggle-track-width, $fallbacks);
 
   &.mdc-switch--disabled {
@@ -367,6 +388,7 @@ $fallbacks: m3-slide-toggle.get-tokens();
   &::after {
     content: '';
     opacity: 0;
+  
 
     .mdc-switch--disabled & {
       display: none;