Update Index table colors (#10755)

### WHY are these changes introduced?

Fixes #10362

### WHAT is this pull request doing?

This updates some Index table row colors as well as the color value for
the `color-bg-surface-selected` token

Author: aveline

polaris-react/src/components/IndexTable/IndexTable.scss

@@ -262,7 +262,7 @@ $loading-panel-height: 53px;
     .TableHeading-second,
     .TableCell-first,
     .TableCell-first + .TableCell {
-      background-color: var(--p-color-bg-primary-subdued-selected);
+      background-color: var(--p-color-bg-surface-selected);
     }
 
     /* stylelint-disable-next-line selector-max-class -- generated by polaris-migrator DO NOT COPY */
@@ -359,7 +359,7 @@ $loading-panel-height: 53px;
     .TableCell-first,
     .TableCell-first + .TableCell,
     .TableCell:last-child {
-      background-color: var(--p-color-bg-primary-subdued-hover);
+      background-color: var(--p-color-bg-surface-hover);
     }
 
     /* stylelint-disable-next-line selector-max-class, selector-max-specificity -- generated by polaris-migrator DO NOT COPY */

polaris-tokens/src/themes/base/color.ts

@@ -433,7 +433,7 @@ export const color: {
     value: colorsExperimental.gray[4],
   },
   'color-bg-surface-selected': {
-    value: colorsExperimental.gray[3],
+    value: colorsExperimental.gray[6],
   },
   'color-bg-fill-success': {
     value: colorsExperimental.green[12],