fix(material/slide-toggle): allow touch target size to be customized

Adds a token that allows for the slide toggle touch target to be customized.

(cherry picked from commit fe865b1)

Author: crisbeto

src/material/slide-toggle/_m2-slide-toggle.scss

@@ -60,6 +60,7 @@
       slide-toggle-visible-track-opacity: 1,
       slide-toggle-visible-track-transition: transform 75ms 0ms cubic-bezier(0, 0, 0.2, 1),
       slide-toggle-with-icon-handle-size: 20px,
+      slide-toggle-touch-target-size: 48px,
     ),
     color: map.merge(private-get-color-palette-color-tokens($theme, primary), (
       slide-toggle-disabled-label-text-color:

src/material/slide-toggle/_m3-slide-toggle.scss

@@ -60,6 +60,7 @@
       slide-toggle-with-icon-handle-size: 24px,
       slide-toggle-handle-width: null,
       slide-toggle-handle-height: null,
+      slide-toggle-touch-target-size: 48px,
     ),
     color: (
       slide-toggle-disabled-label-text-color: map.get($system, on-surface),

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

@@ -548,7 +548,7 @@ $fallbacks: m3-slide-toggle.get-tokens();
   position: absolute;
   top: 50%;
   left: 50%;
-  height: 48px;
+  height: token-utils.slot(slide-toggle-touch-target-size, $fallbacks);
   width: 100%;
   transform: translate(-50%, -50%);
   display: token-utils.slot(slide-toggle-touch-target-display, $fallbacks);