fix(material/paginator): disabled buttons not visible in high contrast mode (#30505)

#29379 changed the selector for disabled buttons from `[disabled]` to `[aria-disabled]`, however it didn't apply the same change to the high contrast styles which led to them being invisible in dark mode.

I've also improved the experience by styling the buttons as disabled in high contrast mode.

Fixes #30504.

Author: crisbeto

src/material/paginator/paginator.scss

@@ -131,17 +131,17 @@ $button-icon-size: 28px;
 
 @include cdk.high-contrast {
   // The disabled button icon has to be set explicitly since the selector is too specific.
-  .mat-mdc-icon-button[disabled] .mat-mdc-paginator-icon,
+  .mat-mdc-icon-button[aria-disabled] .mat-mdc-paginator-icon,
   .mat-mdc-paginator-icon {
     fill: currentColor;
-
-    // On Chromium browsers the `currentColor` blends in with the
-    // background for SVGs so we have to fall back to `CanvasText`.
-    fill: CanvasText;
   }
 
   .mat-mdc-paginator-range-actions .mat-mdc-icon-button {
     outline: solid 1px;
+
+    &[aria-disabled] {
+      color: GrayText;
+    }
   }
 }