Merge pull request #7026 from IgniteUI/didimmova/fix-tooltip-7003

fix(tooltip): make tooltip visible in fluent theme

Author: simeonoff

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

@@ -46,7 +46,10 @@ $_fluent-tooltip: extend(
     $_fluent-shape-tooltip,
     (
         background: (
-            igx-color: 'surface'
+            igx-color: ('grays', 900)
+        ),
+        text-color: (
+            igx-contrast-color: ('grays', 900)
         )
     )
 );