fix(progress-bar, spinner): update colors for ionic theme (#30418)

Issue number: internal

---------

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->
The colors were not working on progress bar when the theme was ionic; 
The Spinner with color="medium" should use the contrast variation by
design;

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->
- Fix Progress-Bar Ionic Colors;
- Change Spinner Medium Color Variation;

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

https://ionic-framework-git-rou-11917-ionic1.vercel.app/src/components/progress-bar/test/basic?ionic:theme=ionic

https://ionic-framework-git-rou-11917-ionic1.vercel.app/src/components/spinner/test/color?ionic:theme=ionic

core/src/components/progress-bar/progress-bar.common.scss

@@ -146,13 +146,6 @@
   }
 }
 
-:host(.ion-color) {
-  .progress,
-  .progress-indeterminate {
-    background: #{current-color(base)};
-  }
-}
-
 // Progress Bar: Animation Keyframes
 // ------------------------------------------------------------------------
 // Source: https://github.com/material-components/material-components-web/blob/master/packages/mdc-linear-progress/_keyframes.scss

core/src/components/progress-bar/progress-bar.ionic.scss

@@ -25,6 +25,13 @@
 // Progress Bar: Color
 // ------------------------------------------------------------------------
 
+:host(.ion-color) {
+  .progress,
+  .progress-indeterminate {
+    background: #{globals.current-color(base)};
+  }
+}
+
 :host(.ion-color) .buffer-circles {
   background-image: radial-gradient(
     ellipse at center,

core/src/components/progress-bar/progress-bar.native.scss

@@ -14,6 +14,13 @@
 // Progress Bar: Color
 // ------------------------------------------------------------------------
 
+:host(.ion-color) {
+  .progress,
+  .progress-indeterminate {
+    background: #{current-color(base)};
+  }
+}
+
 :host(.ion-color) .buffer-circles {
   background-image: radial-gradient(
     ellipse at center,

core/src/components/spinner/spinner.ionic.scss

@@ -11,6 +11,10 @@
   height: globals.$ion-scale-700;
 }
 
+:host(.ion-color-medium) {
+  color: #{globals.ion-color(medium, contrast, $subtle: true)};
+}
+
 // Spinner: lines / lines-small / lines-sharp / lines-sharp-small
 // --------------------------------------------------