Removing flex-basis: 0 to make items size properly in IE11 (#16557)

ui_framework/dist/ui_framework.css

@@ -1162,10 +1162,7 @@ main {
     -webkit-box-flex: 1;
     -webkit-flex-grow: 1;
         -ms-flex-positive: 1;
-            flex-grow: 1;
-    -webkit-flex-basis: 0;
-        -ms-flex-preferred-size: 0;
-            flex-basis: 0; }
+            flex-grow: 1; }
 
 .kuiFlexGroup--gutterSmall {
   margin: -4px; }

ui_framework/src/components/flex/_flex_group.scss

@@ -4,7 +4,6 @@
 
   .kuiFlexItem {
     flex-grow: 1;
-    flex-basis: 0;
   }
 }