feat(material/legacy-progress-bar): step 3. rename sass mixins

Author: wagnermaciel

src/material/_index.scss

@@ -92,8 +92,8 @@
 @forward './menu/menu-theme' as menu-* show menu-theme, menu-color, menu-typography;
 @forward './paginator/paginator-theme' as paginator-* show paginator-theme, paginator-color,
   paginator-typography;
-@forward './legacy-progress-bar/progress-bar-theme' as progress-bar-* show progress-bar-theme,
-  progress-bar-color, progress-bar-typography;
+@forward './legacy-progress-bar/progress-bar-theme' as legacy-progress-bar-* show
+  legacy-progress-bar-theme, progress-bar-color, progress-bar-typography;
 @forward './progress-spinner/progress-spinner-theme' as progress-spinner-* show
   progress-spinner-theme, progress-spinner-color, progress-spinner-typography;
 @forward './radio/radio-theme' as radio-* show radio-theme, radio-color, radio-typography;

src/material/legacy-progress-bar/_progress-bar-legacy-index.scss

@@ -1,2 +1,2 @@
 @forward 'progress-bar-theme' hide color, theme, typography;
-@forward 'progress-bar-theme' as mat-progress-bar-* hide mat-progress-bar-density;
+@forward 'progress-bar-theme' as mat-legacy-progress-bar-* hide mat-legacy-progress-bar-density;

src/material/legacy-progress-bar/_progress-bar-theme.import.scss

@@ -1,6 +1,6 @@
 @forward '../core/theming/theming.import';
 @forward 'progress-bar-theme' hide color, theme, typography;
-@forward 'progress-bar-theme' as mat-progress-bar-* hide mat-progress-bar-density;
+@forward 'progress-bar-theme' as mat-legacy-progress-bar-* hide mat-legacy-progress-bar-density;
 
 @import '../core/theming/palette';
 @import '../core/theming/theming';