Fix comments.

Author: priveraussi

projects/material-css-vars/src/lib/_mat-lib-overwrites.scss

@@ -297,7 +297,7 @@
 }
 
 // ---------------------------
-// Progress Bar component 
+// PROGRESS BAR component 
 // ---------------------------
 @mixin _mat-mdc-progress-bar-overwrites {
   .mat-mdc-progress-bar {
@@ -320,7 +320,7 @@
 }
 
 // ---------------------------
-// Progress Bar component 
+// SLIDER component 
 // ---------------------------
 @mixin _mat-mdc-slider {
   .mat-mdc-slider {