chore: fix error in slider docs (angular#10409)

Fixes a couple of instances that were missed when removing the slider deletion targets.

Author: crisbeto

src/material-examples/slider-configurable/slider-configurable-example.html

@@ -54,8 +54,8 @@ <h2 class="example-h2">Result</h2>
         [max]="max"
         [min]="min"
         [step]="step"
-        [thumb-label]="thumbLabel"
-        [tick-interval]="tickInterval"
+        [thumbLabel]="thumbLabel"
+        [tickInterval]="tickInterval"
         [(ngModel)]="value"
         [vertical]="vertical">
     </mat-slider>