refactor(themes): set avatar size only in card thumbnail (#16268)

* refactor(themes): set avatar size only in card thumbnail

Author: simeonoff

projects/igniteui-angular/src/lib/core/styles/components/card/_card-theme.scss

@@ -29,10 +29,6 @@
         &:hover {
             box-shadow: none;
         }
-
-        igx-avatar {
-            --ig-size: #{if($variant == 'indigo', 3, 1)};
-        }
     }
 
     %igx-card--elevated {
@@ -93,6 +89,10 @@
             margin-block: auto;
         }
 
+        igx-avatar {
+            --ig-size: #{if($variant == 'indigo', 3, 1)};
+        }
+
         &:empty {
             display: none;
         }