fix(switch): use the new thumb hover property (#1809)

Author: didimmova

src/components/checkbox/themes/shared/switch/switch.bootstrap.scss

@@ -65,10 +65,6 @@ $theme: $bootstrap;
         border-color: var-get($theme, 'border-on-hover-color');
     }
 
-    [part~='thumb'] {
-        background: var-get($theme, 'border-hover-color');
-    }
-
     [part~='thumb'][part~='checked'] {
         background: var-get($theme, 'thumb-on-color');
     }

src/components/checkbox/themes/shared/switch/switch.common.scss

@@ -14,6 +14,10 @@ $theme: $material;
     [part~='label'] {
         color: var-get($theme, 'label-hover-color');
     }
+
+    [part~='thumb']:not([part~='checked']) {
+        background: var-get($theme, 'thumb-off-hover-color');
+    }
 }
 
 :host([disabled]),

src/components/checkbox/themes/shared/switch/switch.fluent.scss

@@ -70,10 +70,6 @@ $theme: $fluent;
         border-color: var-get($theme, 'border-on-hover-color');
     }
 
-    [part~='thumb'] {
-        background: var-get($theme, 'border-hover-color');
-    }
-
     [part~='thumb'][part~='checked'] {
         background: var-get($theme, 'thumb-on-color');
     }

src/components/checkbox/themes/shared/switch/switch.indigo.scss

@@ -24,10 +24,6 @@ $border-width: rem(1px);
         border-color: var-get($theme, 'border-hover-color');
     }
 
-    [part~='thumb']:not([part~='checked']) {
-        background: var-get($theme, 'border-hover-color');
-    }
-
     [part~='control'][part~='checked'] {
         background: var-get($theme, 'track-on-hover-color');
         border-color: var-get($theme, 'border-on-hover-color');