fix(material/slide-toggle): m3 disabled handle color and opacity

Author: wagnermaciel

src/material/core/tokens/m2/mat/_switch.scss

@@ -8,6 +8,9 @@ $prefix: (mat, switch);
 // but may be in a future version of the theming API.
 @function get-unthemable-tokens() {
   @return (
+    disabled-selected-handle-opacity: 0.38,
+    disabled-unselected-handle-opacity: 0.38,
+
     unselected-handle-size: 20px,
     selected-handle-size: 20px,
     pressed-handle-size: 20px,

src/material/core/tokens/m2/mdc/_switch.scss

@@ -18,7 +18,7 @@ $prefix: (mdc, switch);
 @function get-unthemable-tokens() {
   @return (
     // Opacity of handle when disabled.
-    disabled-handle-opacity: 0.38,
+    disabled-handle-opacity: null,
     // Opacity of icon when disabled and selected.
     disabled-selected-icon-opacity: 0.38,
     // Opacity of track when disabled.

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

@@ -224,3 +224,13 @@
     @include token-utils.create-token-slot(border, disabled-unselected-track-outline);
   }
 }
+
+@include token-utils.use-tokens(m2-mat-switch.$prefix, m2-mat-switch.get-token-slots()) {
+  .mdc-switch--disabled.mdc-switch--selected .mdc-switch__handle::after {
+    @include token-utils.create-token-slot(opacity, disabled-selected-handle-opacity);
+  }
+
+  .mdc-switch--disabled.mdc-switch--unselected .mdc-switch__handle::after {
+    @include token-utils.create-token-slot(opacity, disabled-unselected-handle-opacity);
+  }
+}