message: fix: color of message bar icon in high contrast mode
  Increased CSS specificity of message bar icon rule so the "Target page is in a hidden state" icon changes color as expected when high contrast mode is applied.
diff: @@ -792,7 +792,7 @@ div.insights-file-issue-details-dialog-container {
  .ms-MessageBar {
  padding-left: 24px;
  }
  - .ms-MessageBar-icon {
  + .ms-MessageBar-icon i {
  color: $secondary-text;
  }
  .target-tab-info {
  