fix(stepper): icon size and title/subtitle colors in bootstrap theme (#12153)

* feat(stepper): fix icon size in bootstrap theme.

* style(theme): revert theme vars to material theme

* style(theme): change title and subtitle colors

Co-authored-by: Simeon Simeonoff <[email protected]>

Author: desig9stein

projects/igniteui-angular/src/lib/core/styles/components/stepper/_stepper-theme.scss

@@ -538,6 +538,12 @@
                 font-size: var(--igx-icon-size, #{calc(#{$indicator-size} - #{rem(6px)})});
                 color: inherit;
             }
+        } @else if $variant == 'bootstrap' {
+            > igx-icon {
+                width: var(--igx-icon-size, #{rem(18px)});
+                height: var(--igx-icon-size, #{rem(18px)});
+                font-size: var(--igx-icon-size, #{rem(18px)});
+            }
         }
 
         div > igx-icon,

projects/igniteui-angular/src/lib/core/styles/themes/schemas/light/_stepper.scss

@@ -320,13 +320,6 @@ $fluent-stepper: extend(
 /// @property {Color} indicator-background [transparent] - The background color of the incomplete step indicator.
 /// @property {Map} indicator-outline [color: ('grays', 300)] - The outline color of the incomplete step indicator.
 ///
-/// @property {Map} current-title-color [color: ('primary', 500)] - The color of the current step title.
-/// @property {Map} current-title-hover-color [color: ('primary', 500)] - The color of the current step title on hover.
-/// @property {Map} current-title-focus-color [color: ('primary', 500)] - The color of the current step title on focus.
-/// @property {Map} current-subtitle-color [color: ('primary', 500)] - The color of the current step subtitle.
-/// @property {Map} current-subtitle-hover-color [color: ('primary', 500)] - The color of the current step subtitle on hover.
-/// @property {Map} current-subtitle-focus-color [color: ('primary', 500)] - The color of the current step subtitle on focus.
-///
 /// @property {Color} disabled-indicator-background [transparent] - The background color of the disabled step indicator.
 /// @property {Map} disabled-indicator-outline [color: ('grays', 300)] - The outline color of the disabled step indicator.
 ///
@@ -392,26 +385,6 @@ $bootstrap-stepper: extend(
             color: ('primary', 500)
         ),
 
-        // Current
-        current-title-color: (
-            color: ('primary', 500)
-        ),
-        current-title-hover-color: (
-            color: ('primary', 500)
-        ),
-        current-title-focus-color: (
-            color: ('primary', 500)
-        ),
-        current-subtitle-color: (
-            color: ('primary', 500)
-        ),
-        current-subtitle-hover-color: (
-            color: ('primary', 500)
-        ),
-        current-subtitle-focus-color: (
-            color: ('primary', 500)
-        ),
-
         // Complete
         complete-indicator-background: (
             color: ('grays', 400)